Dec 132017
Full Description of File
CRUSH v1.3 - Super-compressor for DOS.
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
| CRUSH v1.3 – Super-compressor for DOS. | |||
|---|---|---|---|
| File Name | File Size | Zip Size | Zip Type |
| CRUSH.EXE | 25084 | 24308 | deflated |
| FILE_ID.DIZ | 448 | 312 | deflated |
| HISTORY.DOC | 1245 | 614 | deflated |
| INSTALL.BAT | 485 | 250 | deflated |
| MANUAL.DOC | 42664 | 11786 | deflated |
| ORDER.FRM | 1863 | 645 | deflated |
| PRODUCTS.OTH | 1535 | 798 | deflated |
| README | 13143 | 4832 | deflated |
| README.1ST | 346 | 235 | deflated |
| REGISTER.DOC | 10017 | 4055 | deflated |
| UNCRUSH.EXE | 10108 | 9695 | deflated |
| VENDINFO.DIZ | 10085 | 5183 | deflated |
Download File CRUSH13.ZIP Here
Contents of the README file
CRUSH v1.3 - Super-compressor for DOS.
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
__________________________________________________________________________
CRUSH v1.3 Readme File
__________________________________________________________________________
CRUSH is a new shareware product from the same author as the awarding
winning DOS file manager PocketD Plus ("BEST UTILITY 1992" PsL and joint
runner-up WHAT PC's "BEST UTILITY 1994" with Stacker v4.0 & Dr Solomon's
Virus Toolkit). PocketD Plus has been upgraded to v4.1 to support CRUSH.
>>>>>>>> WHAT IS CRUSH ?
CRUSH is a compression tool that can work with your existing archiver
to dramatically reduce the size of archives created. In many
instances CRUSH achieves an average 2:1 advantage over PKZIP and 8:1
over uncompressed files. However CRUSH is neither slow nor
inconvenient to use. The command-line syntax is essentially similar
to PKZIP, but with many powerful extensions.
CRUSH will work with any of PKZIP, ARJ, LHA, ZOO, UC2 and HA. The
archivers PKZIP, UC2 and ARJ are Shareware and require registration
payments. LHA, ZOO and HA are Copyrighted Freeware.
>>>>>>>> HOW DOES IT WORK ?
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will
generally compress better than small files, a property used by Unix
users who follow the maxim "always tar before compress" (joining
files together before compressing). CRUSH will automatically do this
for you, generating a single file with an extension "CRU" that it
compresses using your chosen archiver (default PKZIP). Extraction of
files is then very easy: UNCRUSH works in the same way as PKUNZIP.
CRUSH gets the most from this compression trick by taking it one step
further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to
recognise 7 different compressed header types), and orders them
accordingly. This yields a very good default fast compression.
Given more time CRUSH can do better by optionally performing a series
of trials to squeeze out extra compression. The algorithm for this
uses an intelligent re-ordering mechanism which analyses the results
of each intermediate test in order to determine which ordering to try
next. This was developed over a period of 2 years where it was
successfully used to reduce the file size of PocketD Plus to the
absolute minimum. This technique allows CRUSH to find near optimum
compression in a few minutes that might take hundreds of years using
more brute-force methods!
>>>>>>>> HOW GOOD IS IT?
Using CRUSH would not be worthwhile if it yielded a narrow advantage
over existing archivers, but in many situations it is capable of
delivering dramatically better compression. The results below are
genuine random tests performed on files taken from a 250-user PC
server and from a publically available CD-ROM.
All archivers were run with maximum compression, except CRUSH which
was set to minimum. The figures for Stacker and DoubleSpace are
commercially quoted performance figures for comparison, not test
results. All the figures quote the compression ratio in terms of disk
space used rather than actual file sizes (8k cluster assumed) to
allow comparison with Stacker 4.0. This does not significantly affect
the comparison between the other archivers (Figures for ZOO are not
quoted as it uses the same compression algorithm as LHA. Figures for
UC2 are not quoted as support for this has only just been added).
>>>>>>>> (1) CRUSH at its BEST -- Working with small data files
CRUSH works best with collections of similar small files. In a block test
of 128 directories (each compressed to its own archive) containing 2349
wordprocessing files (total 33 Megabytes), CRUSH with minimum optimisation
generated the following average compression ratio, calculated by:
Ratio = (disk space used by uncompressed files)/(space after compression)
Ratio
CRUSH+HA 7.95
CRUSH+PKZIP 7.82
CRUSH+ARJ 6.16
CRUSH+LHA 5.46
HA 0.98 4.32
PKZIP 2.04g 4.11
ARJ 2.3 4.18
LHA 2.11 4.12
Stacker 4.0 2.50
DoubleSpace 1.90
Orig Files 1.00
CRUSH clearly yields a substantial improvement in all cases. Its worst
result is with LHA, but this is still much better than any non-CRUSH
compression.
>>>>>>>> HOW FAST IS CRUSH ?
These results might be of limited value if the cost in time for
compression was great. The chart below shows the compression times for 6
wordprocessing files, totalling 150k on a 486SX25 with a ramdrive:
Seconds
CRUSH+HA 11.04
CRUSH+ZIP 3.51
CRUSH+ARJ 3.30
CRUSH+LHA 3.68
CRUSH+ZOO 8.57
HA 0.98 10.98
PKZIP 2.04 2.26
ARJ 2.3 3.02
LHA 2.11 3.30
ZOO 2.1 7.85
From these compression and speed results it can be seem that CRUSH with HA
0.98 offers the best overall compression, but that CRUSH with PKZIP or ARJ
does nearly as well, but are both over 3 times faster.
>>>>>>>> (2) CRUSH at its WORST -- Working with large or dissimilar files
CRUSH has the most difficulty when given large or dissimilar files. A good
example of this might be a Shareware release file which contains a mixture
of documents, executable and other files. A test with minimum optimisation
on 40 random archive files from the ASP-CD ROM (17 Megabytes) yielded the
following results:
Ratio
CRUSH+HA 2.84
CRUSH+ZIP 2.80
HA 0.98 2.76
PKZIP 2.04g 2.70
ARJ 2.3 2.70
LHA 2.11 2.66
Stacker 4.0 (2.50)
Doublespace (1.90)
Orig Files 1.00
Here, improved performance is somewhat less than the previous example,
corresponding to a 3.7% improvement with PKZIP. Many of the compressions
yielded a 0% improvement because although the newly compressed file may
have been smaller, it still occupied the same number of disk allocation
units (clusters). The average improvement in actual file size (important
for file downloads) was 5.6% for PKZIP, with a low of 1% and high of 28%.
The figures for Stacker and DoubleSpace are bracketed as they almost
certainly greatly overestimate their performances in these cases.
>>>>>>>> I USE STACKER. IS THERE MERIT IN USING CRUSH ?
On the fly compression provided by products such as Stacker offers
convenient but low performance compression. Stacker may make your 100 Mb
drive look like 250 Mb, but CRUSH may make it look like 800 Mb. On the fly
compression also has performance penalties and there is a question mark
over its safety.
Of course, CRUSH can safely be used in conjunction with Stacker to obtain
the highest possible net space saving.
>>>>>>>> IS IT WORTH MY WHILE USING CRUSH ?
If your PC is loaded with applications, but little data, then CRUSH may
not help that much. If your PC or PC server typically holds many source
files, database files or wordprocessing documents, then the advantages
might be enormous. A beta test site for CRUSH had vast numbers of
wordprocessing files for which CRUSH was able to achieve a compression
ratio of 16:1 where PKZIP had only yielded 6:1.
>>>>>>>> ARE THERE ANY DRAWBACKS IN USING CRUSH ?
CRUSH requires a significant quantity of temporary filespace whilst
compressing. In the default mode it will typically need 3.0 Mb of
temporary disk space available in order to compress 2.0 Mb of files. The
same is true when uncompressing. To extract a single 1k file from an
archive that contains 1 Mb will require 1 Mb of temporary file space.
CRUSH will not allow the user to update a single file or group of files
within a CRUSH archive. The entire archive must be re-created. It will
therefore be less useful to users who want to regularly update the same
archive to reflect frequent changes.
CRUSH is new and therefore many 3rd party programs will not yet be able to
search or view CRUSHed files. However these will appear, and the very
capable PocketD Plus v4.1 can already do this, allowing viewing of files
inside CRUSH archives with the same ease as any other archive type.
>>>>>>>> ARE THERE ANY OTHER ADVANTAGES IN USING CRUSH ?
CRUSH supports features such as recursive directory searching, storing of
paths, archive comments, file inclusion/exclusion by name and date, as
other archivers. However CRUSH also adds its own special facilities.
1. On-line Selection of Files
CRUSH allows the user to select files for archiving from an on-line
prompt, rather than forcing files to be always explicitly specified
in the command-line. This allows the user to issue commands such as
"Search the drive for files matching *.C modified during the last 6
days and present each matching name for acceptance or rejection".
2. Automatic Archive Name Generation
CRUSH has an option to automatically generate unique archive names
based on the current date and time. This is an ideal mechanism for
creating multiple generation backups.
3. Relative and Backup Date Testing
Unlike programs such as ARJ and PKZIP, CRUSH allows relative dates to
be specified, e.g. "CRUSH -r:-4 BACKUP" will search for and compress
files modified today or during the previous 4 days. CRUSH also allows
a "compress-since-last-backup" feature by allowing the comparison
with a named file date and time, e.g. "CRUSH -:.LASTBAC BACKUP" will
compress files modified since the date and time of the file LASTBAC.
4. Safer Decompression
UNCRUSH will helpfully tell you that a file to be de-compressed
already exists, and also if it is older, newer or identical.
5. CRUSH Supports Proper Wildcards
Unlike DOS (and PKZIP etc.), CRUSH supports proper wildcards. e.g.
the DOS wildcard *FRED.* would match a file called JOE! CRUSH
correctly implements "*" as any sequence of characters (including
none) and "?" as a single character.
6. User-specified Thresholds
CRUSH can be set to create a conventional archive where it cannot
improve by a specified percentage improved compression.
>>>>>>>> HOW DO I COMPARE CRUSH AND PKZIP (OR OTHER) PERFORMANCE ?
CRUSH has a convenient option "-c" which will run the chosen archiver
as well as performing a CRUSH archive operation. The results of this
are displayed as a bar graph (or table, if required).
>>>>>>>> HOW MUCH EXTRA WILL MAXIMUM CRUSH COMPRESSION GIVE ?
The cost in time for turning on extra optimisation in CRUSH is large.
Adding the -f option will probably increase compression time by a
factor of 5-10 times the default minimum, probably yielding between
1%-10% extra compression. However if you want to compress to the
minimum, then you may be happy to leave it overnight with -f200!
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
__________________________________________________________________________
CRUSH v1.3 Readme File
__________________________________________________________________________
CRUSH is a new shareware product from the same author as the awarding
winning DOS file manager PocketD Plus ("BEST UTILITY 1992" PsL and joint
runner-up WHAT PC's "BEST UTILITY 1994" with Stacker v4.0 & Dr Solomon's
Virus Toolkit). PocketD Plus has been upgraded to v4.1 to support CRUSH.
>>>>>>>> WHAT IS CRUSH ?
CRUSH is a compression tool that can work with your existing archiver
to dramatically reduce the size of archives created. In many
instances CRUSH achieves an average 2:1 advantage over PKZIP and 8:1
over uncompressed files. However CRUSH is neither slow nor
inconvenient to use. The command-line syntax is essentially similar
to PKZIP, but with many powerful extensions.
CRUSH will work with any of PKZIP, ARJ, LHA, ZOO, UC2 and HA. The
archivers PKZIP, UC2 and ARJ are Shareware and require registration
payments. LHA, ZOO and HA are Copyrighted Freeware.
>>>>>>>> HOW DOES IT WORK ?
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will
generally compress better than small files, a property used by Unix
users who follow the maxim "always tar before compress" (joining
files together before compressing). CRUSH will automatically do this
for you, generating a single file with an extension "CRU" that it
compresses using your chosen archiver (default PKZIP). Extraction of
files is then very easy: UNCRUSH works in the same way as PKUNZIP.
CRUSH gets the most from this compression trick by taking it one step
further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to
recognise 7 different compressed header types), and orders them
accordingly. This yields a very good default fast compression.
Given more time CRUSH can do better by optionally performing a series
of trials to squeeze out extra compression. The algorithm for this
uses an intelligent re-ordering mechanism which analyses the results
of each intermediate test in order to determine which ordering to try
next. This was developed over a period of 2 years where it was
successfully used to reduce the file size of PocketD Plus to the
absolute minimum. This technique allows CRUSH to find near optimum
compression in a few minutes that might take hundreds of years using
more brute-force methods!
>>>>>>>> HOW GOOD IS IT?
Using CRUSH would not be worthwhile if it yielded a narrow advantage
over existing archivers, but in many situations it is capable of
delivering dramatically better compression. The results below are
genuine random tests performed on files taken from a 250-user PC
server and from a publically available CD-ROM.
All archivers were run with maximum compression, except CRUSH which
was set to minimum. The figures for Stacker and DoubleSpace are
commercially quoted performance figures for comparison, not test
results. All the figures quote the compression ratio in terms of disk
space used rather than actual file sizes (8k cluster assumed) to
allow comparison with Stacker 4.0. This does not significantly affect
the comparison between the other archivers (Figures for ZOO are not
quoted as it uses the same compression algorithm as LHA. Figures for
UC2 are not quoted as support for this has only just been added).
>>>>>>>> (1) CRUSH at its BEST -- Working with small data files
CRUSH works best with collections of similar small files. In a block test
of 128 directories (each compressed to its own archive) containing 2349
wordprocessing files (total 33 Megabytes), CRUSH with minimum optimisation
generated the following average compression ratio, calculated by:
Ratio = (disk space used by uncompressed files)/(space after compression)
Ratio
CRUSH+HA 7.95
CRUSH+PKZIP 7.82
CRUSH+ARJ 6.16
CRUSH+LHA 5.46
HA 0.98 4.32
PKZIP 2.04g 4.11
ARJ 2.3 4.18
LHA 2.11 4.12
Stacker 4.0 2.50
DoubleSpace 1.90
Orig Files 1.00
CRUSH clearly yields a substantial improvement in all cases. Its worst
result is with LHA, but this is still much better than any non-CRUSH
compression.
>>>>>>>> HOW FAST IS CRUSH ?
These results might be of limited value if the cost in time for
compression was great. The chart below shows the compression times for 6
wordprocessing files, totalling 150k on a 486SX25 with a ramdrive:
Seconds
CRUSH+HA 11.04
CRUSH+ZIP 3.51
CRUSH+ARJ 3.30
CRUSH+LHA 3.68
CRUSH+ZOO 8.57
HA 0.98 10.98
PKZIP 2.04 2.26
ARJ 2.3 3.02
LHA 2.11 3.30
ZOO 2.1 7.85
From these compression and speed results it can be seem that CRUSH with HA
0.98 offers the best overall compression, but that CRUSH with PKZIP or ARJ
does nearly as well, but are both over 3 times faster.
>>>>>>>> (2) CRUSH at its WORST -- Working with large or dissimilar files
CRUSH has the most difficulty when given large or dissimilar files. A good
example of this might be a Shareware release file which contains a mixture
of documents, executable and other files. A test with minimum optimisation
on 40 random archive files from the ASP-CD ROM (17 Megabytes) yielded the
following results:
Ratio
CRUSH+HA 2.84
CRUSH+ZIP 2.80
HA 0.98 2.76
PKZIP 2.04g 2.70
ARJ 2.3 2.70
LHA 2.11 2.66
Stacker 4.0 (2.50)
Doublespace (1.90)
Orig Files 1.00
Here, improved performance is somewhat less than the previous example,
corresponding to a 3.7% improvement with PKZIP. Many of the compressions
yielded a 0% improvement because although the newly compressed file may
have been smaller, it still occupied the same number of disk allocation
units (clusters). The average improvement in actual file size (important
for file downloads) was 5.6% for PKZIP, with a low of 1% and high of 28%.
The figures for Stacker and DoubleSpace are bracketed as they almost
certainly greatly overestimate their performances in these cases.
>>>>>>>> I USE STACKER. IS THERE MERIT IN USING CRUSH ?
On the fly compression provided by products such as Stacker offers
convenient but low performance compression. Stacker may make your 100 Mb
drive look like 250 Mb, but CRUSH may make it look like 800 Mb. On the fly
compression also has performance penalties and there is a question mark
over its safety.
Of course, CRUSH can safely be used in conjunction with Stacker to obtain
the highest possible net space saving.
>>>>>>>> IS IT WORTH MY WHILE USING CRUSH ?
If your PC is loaded with applications, but little data, then CRUSH may
not help that much. If your PC or PC server typically holds many source
files, database files or wordprocessing documents, then the advantages
might be enormous. A beta test site for CRUSH had vast numbers of
wordprocessing files for which CRUSH was able to achieve a compression
ratio of 16:1 where PKZIP had only yielded 6:1.
>>>>>>>> ARE THERE ANY DRAWBACKS IN USING CRUSH ?
CRUSH requires a significant quantity of temporary filespace whilst
compressing. In the default mode it will typically need 3.0 Mb of
temporary disk space available in order to compress 2.0 Mb of files. The
same is true when uncompressing. To extract a single 1k file from an
archive that contains 1 Mb will require 1 Mb of temporary file space.
CRUSH will not allow the user to update a single file or group of files
within a CRUSH archive. The entire archive must be re-created. It will
therefore be less useful to users who want to regularly update the same
archive to reflect frequent changes.
CRUSH is new and therefore many 3rd party programs will not yet be able to
search or view CRUSHed files. However these will appear, and the very
capable PocketD Plus v4.1 can already do this, allowing viewing of files
inside CRUSH archives with the same ease as any other archive type.
>>>>>>>> ARE THERE ANY OTHER ADVANTAGES IN USING CRUSH ?
CRUSH supports features such as recursive directory searching, storing of
paths, archive comments, file inclusion/exclusion by name and date, as
other archivers. However CRUSH also adds its own special facilities.
1. On-line Selection of Files
CRUSH allows the user to select files for archiving from an on-line
prompt, rather than forcing files to be always explicitly specified
in the command-line. This allows the user to issue commands such as
"Search the drive for files matching *.C modified during the last 6
days and present each matching name for acceptance or rejection".
2. Automatic Archive Name Generation
CRUSH has an option to automatically generate unique archive names
based on the current date and time. This is an ideal mechanism for
creating multiple generation backups.
3. Relative and Backup Date Testing
Unlike programs such as ARJ and PKZIP, CRUSH allows relative dates to
be specified, e.g. "CRUSH -r:-4 BACKUP" will search for and compress
files modified today or during the previous 4 days. CRUSH also allows
a "compress-since-last-backup" feature by allowing the comparison
with a named file date and time, e.g. "CRUSH -:.LASTBAC BACKUP" will
compress files modified since the date and time of the file LASTBAC.
4. Safer Decompression
UNCRUSH will helpfully tell you that a file to be de-compressed
already exists, and also if it is older, newer or identical.
5. CRUSH Supports Proper Wildcards
Unlike DOS (and PKZIP etc.), CRUSH supports proper wildcards. e.g.
the DOS wildcard *FRED.* would match a file called JOE! CRUSH
correctly implements "*" as any sequence of characters (including
none) and "?" as a single character.
6. User-specified Thresholds
CRUSH can be set to create a conventional archive where it cannot
improve by a specified percentage improved compression.
>>>>>>>> HOW DO I COMPARE CRUSH AND PKZIP (OR OTHER) PERFORMANCE ?
CRUSH has a convenient option "-c" which will run the chosen archiver
as well as performing a CRUSH archive operation. The results of this
are displayed as a bar graph (or table, if required).
>>>>>>>> HOW MUCH EXTRA WILL MAXIMUM CRUSH COMPRESSION GIVE ?
The cost in time for turning on extra optimisation in CRUSH is large.
Adding the -f option will probably increase compression time by a
factor of 5-10 times the default minimum, probably yielding between
1%-10% extra compression. However if you want to compress to the
minimum, then you may be happy to leave it overnight with -f200!
Contents of the MANUAL.DOC file
CRUSH v1.3 - Super-compressor for DOS.
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
__________________________________________________________________________
CRUSH v1.3 Readme File
__________________________________________________________________________
CRUSH is a new shareware product from the same author as the awarding
winning DOS file manager PocketD Plus ("BEST UTILITY 1992" PsL and joint
runner-up WHAT PC's "BEST UTILITY 1994" with Stacker v4.0 & Dr Solomon's
Virus Toolkit). PocketD Plus has been upgraded to v4.1 to support CRUSH.
>>>>>>>> WHAT IS CRUSH ?
CRUSH is a compression tool that can work with your existing archiver
to dramatically reduce the size of archives created. In many
instances CRUSH achieves an average 2:1 advantage over PKZIP and 8:1
over uncompressed files. However CRUSH is neither slow nor
inconvenient to use. The command-line syntax is essentially similar
to PKZIP, but with many powerful extensions.
CRUSH will work with any of PKZIP, ARJ, LHA, ZOO, UC2 and HA. The
archivers PKZIP, UC2 and ARJ are Shareware and require registration
payments. LHA, ZOO and HA are Copyrighted Freeware.
>>>>>>>> HOW DOES IT WORK ?
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will
generally compress better than small files, a property used by Unix
users who follow the maxim "always tar before compress" (joining
files together before compressing). CRUSH will automatically do this
for you, generating a single file with an extension "CRU" that it
compresses using your chosen archiver (default PKZIP). Extraction of
files is then very easy: UNCRUSH works in the same way as PKUNZIP.
CRUSH gets the most from this compression trick by taking it one step
further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to
recognise 7 different compressed header types), and orders them
accordingly. This yields a very good default fast compression.
Given more time CRUSH can do better by optionally performing a series
of trials to squeeze out extra compression. The algorithm for this
uses an intelligent re-ordering mechanism which analyses the results
of each intermediate test in order to determine which ordering to try
next. This was developed over a period of 2 years where it was
successfully used to reduce the file size of PocketD Plus to the
absolute minimum. This technique allows CRUSH to find near optimum
compression in a few minutes that might take hundreds of years using
more brute-force methods!
>>>>>>>> HOW GOOD IS IT?
Using CRUSH would not be worthwhile if it yielded a narrow advantage
over existing archivers, but in many situations it is capable of
delivering dramatically better compression. The results below are
genuine random tests performed on files taken from a 250-user PC
server and from a publically available CD-ROM.
All archivers were run with maximum compression, except CRUSH which
was set to minimum. The figures for Stacker and DoubleSpace are
commercially quoted performance figures for comparison, not test
results. All the figures quote the compression ratio in terms of disk
space used rather than actual file sizes (8k cluster assumed) to
allow comparison with Stacker 4.0. This does not significantly affect
the comparison between the other archivers (Figures for ZOO are not
quoted as it uses the same compression algorithm as LHA. Figures for
UC2 are not quoted as support for this has only just been added).
>>>>>>>> (1) CRUSH at its BEST -- Working with small data files
CRUSH works best with collections of similar small files. In a block test
of 128 directories (each compressed to its own archive) containing 2349
wordprocessing files (total 33 Megabytes), CRUSH with minimum optimisation
generated the following average compression ratio, calculated by:
Ratio = (disk space used by uncompressed files)/(space after compression)
Ratio
CRUSH+HA 7.95
CRUSH+PKZIP 7.82
CRUSH+ARJ 6.16
CRUSH+LHA 5.46
HA 0.98 4.32
PKZIP 2.04g 4.11
ARJ 2.3 4.18
LHA 2.11 4.12
Stacker 4.0 2.50
DoubleSpace 1.90
Orig Files 1.00
CRUSH clearly yields a substantial improvement in all cases. Its worst
result is with LHA, but this is still much better than any non-CRUSH
compression.
>>>>>>>> HOW FAST IS CRUSH ?
These results might be of limited value if the cost in time for
compression was great. The chart below shows the compression times for 6
wordprocessing files, totalling 150k on a 486SX25 with a ramdrive:
Seconds
CRUSH+HA 11.04
CRUSH+ZIP 3.51
CRUSH+ARJ 3.30
CRUSH+LHA 3.68
CRUSH+ZOO 8.57
HA 0.98 10.98
PKZIP 2.04 2.26
ARJ 2.3 3.02
LHA 2.11 3.30
ZOO 2.1 7.85
From these compression and speed results it can be seem that CRUSH with HA
0.98 offers the best overall compression, but that CRUSH with PKZIP or ARJ
does nearly as well, but are both over 3 times faster.
>>>>>>>> (2) CRUSH at its WORST -- Working with large or dissimilar files
CRUSH has the most difficulty when given large or dissimilar files. A good
example of this might be a Shareware release file which contains a mixture
of documents, executable and other files. A test with minimum optimisation
on 40 random archive files from the ASP-CD ROM (17 Megabytes) yielded the
following results:
Ratio
CRUSH+HA 2.84
CRUSH+ZIP 2.80
HA 0.98 2.76
PKZIP 2.04g 2.70
ARJ 2.3 2.70
LHA 2.11 2.66
Stacker 4.0 (2.50)
Doublespace (1.90)
Orig Files 1.00
Here, improved performance is somewhat less than the previous example,
corresponding to a 3.7% improvement with PKZIP. Many of the compressions
yielded a 0% improvement because although the newly compressed file may
have been smaller, it still occupied the same number of disk allocation
units (clusters). The average improvement in actual file size (important
for file downloads) was 5.6% for PKZIP, with a low of 1% and high of 28%.
The figures for Stacker and DoubleSpace are bracketed as they almost
certainly greatly overestimate their performances in these cases.
>>>>>>>> I USE STACKER. IS THERE MERIT IN USING CRUSH ?
On the fly compression provided by products such as Stacker offers
convenient but low performance compression. Stacker may make your 100 Mb
drive look like 250 Mb, but CRUSH may make it look like 800 Mb. On the fly
compression also has performance penalties and there is a question mark
over its safety.
Of course, CRUSH can safely be used in conjunction with Stacker to obtain
the highest possible net space saving.
>>>>>>>> IS IT WORTH MY WHILE USING CRUSH ?
If your PC is loaded with applications, but little data, then CRUSH may
not help that much. If your PC or PC server typically holds many source
files, database files or wordprocessing documents, then the advantages
might be enormous. A beta test site for CRUSH had vast numbers of
wordprocessing files for which CRUSH was able to achieve a compression
ratio of 16:1 where PKZIP had only yielded 6:1.
>>>>>>>> ARE THERE ANY DRAWBACKS IN USING CRUSH ?
CRUSH requires a significant quantity of temporary filespace whilst
compressing. In the default mode it will typically need 3.0 Mb of
temporary disk space available in order to compress 2.0 Mb of files. The
same is true when uncompressing. To extract a single 1k file from an
archive that contains 1 Mb will require 1 Mb of temporary file space.
CRUSH will not allow the user to update a single file or group of files
within a CRUSH archive. The entire archive must be re-created. It will
therefore be less useful to users who want to regularly update the same
archive to reflect frequent changes.
CRUSH is new and therefore many 3rd party programs will not yet be able to
search or view CRUSHed files. However these will appear, and the very
capable PocketD Plus v4.1 can already do this, allowing viewing of files
inside CRUSH archives with the same ease as any other archive type.
>>>>>>>> ARE THERE ANY OTHER ADVANTAGES IN USING CRUSH ?
CRUSH supports features such as recursive directory searching, storing of
paths, archive comments, file inclusion/exclusion by name and date, as
other archivers. However CRUSH also adds its own special facilities.
1. On-line Selection of Files
CRUSH allows the user to select files for archiving from an on-line
prompt, rather than forcing files to be always explicitly specified
in the command-line. This allows the user to issue commands such as
"Search the drive for files matching *.C modified during the last 6
days and present each matching name for acceptance or rejection".
2. Automatic Archive Name Generation
CRUSH has an option to automatically generate unique archive names
based on the current date and time. This is an ideal mechanism for
creating multiple generation backups.
3. Relative and Backup Date Testing
Unlike programs such as ARJ and PKZIP, CRUSH allows relative dates to
be specified, e.g. "CRUSH -r:-4 BACKUP" will search for and compress
files modified today or during the previous 4 days. CRUSH also allows
a "compress-since-last-backup" feature by allowing the comparison
with a named file date and time, e.g. "CRUSH -:.LASTBAC BACKUP" will
compress files modified since the date and time of the file LASTBAC.
4. Safer Decompression
UNCRUSH will helpfully tell you that a file to be de-compressed
already exists, and also if it is older, newer or identical.
5. CRUSH Supports Proper Wildcards
Unlike DOS (and PKZIP etc.), CRUSH supports proper wildcards. e.g.
the DOS wildcard *FRED.* would match a file called JOE! CRUSH
correctly implements "*" as any sequence of characters (including
none) and "?" as a single character.
6. User-specified Thresholds
CRUSH can be set to create a conventional archive where it cannot
improve by a specified percentage improved compression.
>>>>>>>> HOW DO I COMPARE CRUSH AND PKZIP (OR OTHER) PERFORMANCE ?
CRUSH has a convenient option "-c" which will run the chosen archiver
as well as performing a CRUSH archive operation. The results of this
are displayed as a bar graph (or table, if required).
>>>>>>>> HOW MUCH EXTRA WILL MAXIMUM CRUSH COMPRESSION GIVE ?
The cost in time for turning on extra optimisation in CRUSH is large.
Adding the -f option will probably increase compression time by a
factor of 5-10 times the default minimum, probably yielding between
1%-10% extra compression. However if you want to compress to the
minimum, then you may be happy to leave it overnight with -f200!
_________________________________
CRUSH v1.3
**** Shareware Manual ****
__________________________________
File Compression Tool
CRUSH (TM) Copyright Jeff Rollason, PocketWare (TM) 1994
All Rights Reserved
All Trademarks Are Acknowledged
No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated
into any other language in whole or in part, in any form or
by any means, whether it be electronic, mechanical,
magnetic, optical, manual or otherwise, without prior
written consent of PocketWare.
PocketWare PO Box 2369, Hendon, London NW4 1NR, England.
CIS 100031,3537. Internet [email protected]
__________________________________________________________________________
Contents:
CONTENTS: Page
Getting Started: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The CRUSH program: . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Default use of PKZIP . . . . . . . . . . . . . . . . . . . . . . . 3
-j Use ARJ . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-o Use ZOO . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-l Use LHA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-h Use HA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-u Use UC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-m Moves file to archive . . . . . . . . . . . . . . . . . . . . 3
-c Compare with and without CRUSH . . . . . . . . . . . . . . . 3
-f Optimise until 5 failed attempts to improve compression . . . 4
-f Optimise until "n" failed attempts to improve compression . . 4
-t Only create CRUSH archive if 5% improvement . . . . . . . . . 4
-t Only create CRUSH archive if "n"% improvement . . . . . . . . 4
-r Recurse subdirectories . . . . . . . . . . . . . . . . . . . 4
-: Set range(s) of dates . . . . . . . . . . . . . . . . . . . . 5
-x Exclude pathspecs . . . . . . . . . . . . . . . . . . . . . . 6
-y Answer YES to all questions . . . . . . . . . . . . . . . . . 6
-z Add CRUSH archive comment . . . . . . . . . . . . . . . . . . 6
-v Show files for adding without CRUSHing . . . . . . . . . . . 6
-n Store files without paths . . . . . . . . . . . . . . . . . . 7
-Q Query each file to be archived. . . . . . . . . . . . . . . . 7
-q QUIET mode, no output . . . . . . . . . . . . . . . . . . . . 7
-a Create an additional index . . . . . . . . . . . . . . . . . 7
-e Use the existing archive for comparison . . . . . . . . . . . 7
-C Colour off . . . . . . . . . . . . . . . . . . . . . . . . . 8
-C Set colour . . . . . . . . . . . . . . . . . . . . . . . . . 8
-s Minimise temporary disk space (slow!) . . . . . . . . . . . . 8
-i Control information type . . . . . . . . . . . . . . . . . . 8
-2 Set display of times to 24 hour clock . . . . . . . . . . . . 8
The UNCRUSH Program: . . . . . . . . . . . . . . . . . . . . . . . . . . 9
-v Display without uncompressing . . . . . . . . . . . . . . . .10
-V Display archive comment only . . . . . . . . . . . . . . . .10
-o Overwrite files without query . . . . . . . . . . . . . . . .10
-u Uncompress NEWER or NEW files . . . . . . . . . . . . . . . .10
-a Uncompress NEW files . . . . . . . . . . . . . . . . . . . .10
-i Ignore paths in CRUSH file . . . . . . . . . . . . . . . . .10
-I Only ignore drives in paths . . . . . . . . . . . . . . . . .10
-q Quiet mode: No output at all . . . . . . . . . . . . . . . .11
-z Only suppress output of archiver . . . . . . . . . . . . . .11
-e Extract even if not CRUSH archive . . . . . . . . . . . . . .11
-l Only display a simple file list . . . . . . . . . . . . . . .11
-2 Display times as 24-hour clock . . . . . . . . . . . . . . .11
Worked Examples: . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
The UNDO and UNDO2 Programs: . . . . . . . . . . . . . . . . . . . . . .13
Configuration: . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Technical Details: . . . . . . . . . . . . . . . . . . . . . . . . . . .15
_________________________________________________________________________
Getting Started Page 1
____________________________________
Installation
CRUSH installation is very simple. The user need only copy the contents of
the release disk to the desired directory. A file INSTALL.BAT is provided
to do this for you. Your chosen directory should be within your search
path (See the PATH variable in your DOS documentation).
In order to be able to use CRUSH, you must have one of the archivers
PKZIP, ARJ, LHA, ZOO, HA and UC.
____________________________________
What is CRUSH?
CRUSH is a command-line tool that uses your existing archiver PKZIP, ARJ,
LHA, ZOO, HA or UC to generate smaller archives than it could alone. With
many applications this improvement may be less than 5%, but dramatic
improvements of 10%-70% are much more typical. A block test of 128
archives totalling 2349 wordprocessing files (see README) averaged a 47%
improvement (100k ZIP reduced to 53k CRUSH!). CRUSH is ideally suited to
users who regularly archive material or who just need to save disk space.
There is no other compression tool for DOS (as of June 1994) that can
match the compression performance of CRUSH, and most do not come close.
____________________________________
CRUSH and other Archivers
CRUSH is used from the command-line in much the same way as archivers such
as PKZIP and ARJ. If you are already familiar with these, then you should
be able to adapt to CRUSH with very little difficulty. If you are a ZOO,
LHA or HA user, then you will observe some changes, but will find the
basic operation of CRUSH very similar.
____________________________________
Simple use of CRUSH
To create a CRUSH archive called BACKUP containing all the files in the
current directory requires the following simple command:
CRUSH BACKUP
This will create the file BACKUP.ZIP (PKZIP must be available). The user
can be more selective by adding filespecs, as follows:
CRUSH BACKUP *.DOC README MAN*.*
This will only save files with the specified filespecs. The user may also
want to receive some feedback about how much space is being saved. The
"-c" (compare) option will allow a comparison to be made:
CRUSH -c BACKUP *.DOC README MAN*.*
Once created, a CRUSH archive can be uncompressed using UNCRUSH in much
the same way as PKUNZIP is used. e.g. UNCRUSH BACKUP *.DOC. This only
extracts files matching *.DOC. The user is advised to read the "Worked
Examples" section for more details of CRUSH usage, and also the README
file. Simply type "CRUSH" to obtain on-line help.
_________________________________________________________________________
The CRUSH program Page 2
This is the program that will replace the use of PKZIP, LHA, ARJ, ZOO, HA
and UC. Whichever of these you already use will still be needed, but CRUSH
will run it for you. The command-line syntax of CRUSH is, for most cases,
identical to PKZIP usage. CRUSH preserves dates, times and attributes.
USAGE: CRUSH [opts] archive [pathspecs] [@lists] [>outfile]
Where:
[opts] These are options that control CRUSH's behaviour. e.g. -r
causes CRUSH to search subdirectories. These can be grouped
together for brevity or specified one-by-one, e.g.
-rca is equivalent to: -r -c -a
The user can choose to use "/" in place of "-" for
preference. e.g. -r and /r are equivalent.
archive This is the name of the archive to be created e.g. BACKUP
or BACKUP.001 etc. If no extension is specified, then the
default extension for the archiver used will be adopted
(default PKZIP). If the special name "[]" is given (e.g.
CRUSH []), then CRUSH will generate a unique archive name
based on the current date and time (assuming that archives
are not created within 2 seconds of each other).
[pathspecs] These are the files to be compressed (defaulting to all
files in the current directory). e.g.
CRUSH SAVE \WP\*.DOC *.TXT
This will compress into SAVE.ZIP all files matching *.DOC
from the directory \WP and all files matching *.TXT from
the current directory. The path \WP\ will also be stored in
the archive, to be re-created by UNCRUSH. UNCRUSH can
optionally ignore stored pathnames.
CRUSH uses proper rather than DOS wildcards. e.g. the DOS
wildcard *FRED.* will match a file called JOE because
*FRED.* and *.* are treated by DOS as equivalent. CRUSH
interprets "*" as any sequence of characters, including
zero length. See also the "-x" EXCLUSION filespecs.
[@lists] CRUSH will accept response files containing lists of files
to be processed. These should contain one pathspec per line
and can contain comments starting with ";" e.g.
*.EXE
\WP\*.DOC ; save my docs
; Fred's stuff here onwards
\BIN\*.EXE
Unlike PKZIP, the response file can be of any length (PKZIP
limits the user to 500 filespecs).
[>outfile] CRUSH can generate a response file by re-directing the
output to a file for later use e.g. CRUSH DOCS >SAVE
__________________________________________________________________________
CRUSH Options Page 3
CRUSH will default to using PKZIP unless -j, -o, -l, -h or -u is
specified. PKZIP is the world's best known archiver, written by Paul Katz
and marketed as Shareware by PKWARE. CRUSH will work with any version of
PKZIP, but the user is recommended to use PKZIP v2.04 or later, which
achieves significantly better compression than v1.x.
____________________________________
-j Use ARJ
This instructs CRUSH to use Robert K Jung's "ARJ" program instead of
PKZIP. This can be specified as a general default using the CRUSH
environment variable e.g. SET CRUSH=-j
Example:
CRUSH BACKUP Use PKZIP
CRUSH -j BACKUP Use ARJ
____________________________________
-o Use ZOO
This will use the ZOO program, creating ZOO files.
____________________________________
-l Use LHA
This will use Haruyasu Yoshizaki's "LHA" program, creating LZH files.
____________________________________
-h Use HA
This will use Harri Hirvola's "HA" program, creating HA files. HA
produces very small archives, but is quite slow.
____________________________________
-u Use UC2
This uses Ad Infinitum Programs's "UC" program. This uses a great of
DOS memory and will probably require the added program US.EXE to
allow CRUSH access to the 80k it needs. e.g. US CRUSH -u SAVE
____________________________________
-m Moves file to archive
This will delete the original files after they have been successfully
compressed.
____________________________________
-c Compare with and without CRUSH
This allows CRUSH to show how much filespace has been saved over the
archiver alone. This will make CRUSH slower as an additional
compression is needed in order to make a comparison (unless -e is
also used). The results are displayed as a bar graph, plotting
archive and CRUSH sizes. The original file size can also be plotted
by adding the option -i2.
__________________________________________________________________________
CRUSH Options Page 4
____________________________________
-f Optimise until 5 failed attempts to improve compression
This will make CRUSH experiment with different orderings to improve
the compression. CRUSH will end when it has failed 5 times to find an
improvement. This will increase the run time of CRUSH by at least 5
times. Each time it provides an improvement, the time taken
increases. CRUSH is unlikely to take more than 15 times the normal
compress time.
The results of this trial are displayed as two bar graphs, showing
the size of the first and best CRUSH compression. (See option "-s").
____________________________________
-f Optimise until "n" failed attempts to improve compression
As "-f", but allowing the user to specify how long CRUSH is to
continue the trial before giving up e.g.
CRUSH -f2 BACKUP will give up after only 2 failures.
CRUSH -f100 BACKUP will give up after 100 failures.
____________________________________
-t Only create CRUSH archive if 5% improvement
This creates a CRUSH archive only if it can improve the archive size
by 5%, otherwise it creates a conventional archive. It invokes the -c
option, which adds to the run time, as it needs to run the archiver
without CRUSH for comparison.
____________________________________
-t Only create CRUSH archive if "n"% improvement
As "-t", but allowing the user to set the threshold e.g.
CRUSH -t10 BACKUP CRUSH only if 10% better
____________________________________
-r Recurse subdirectories
This will search subdirectories from the specified directories, also
storing paths in the archive. Unlike PKZIP, CRUSH defaults to storing
pathnames with the files. However this is done in a very efficient
manner and so does not significantly increase the archive size (PKZIP
uses a space-consuming format for this e.g. searching a subdirectory
DOCUMENT\MYDOCS with 100 files would require an extra 1660 bytes,
whereas CRUSH would require just 16). Example:
CRUSH -r BACKUP \WP\DOCS\*.WP *.TXT
This will search \WP\DOCS and all its subdirectories for the filespec
*.WP, and the current directory and its subdirectories for *.TXT.
CRUSH will store the full path e.g. \WP\DOCS\HOME\DOC.WP etc.
See also the CRUSH option "-n" and UNCRUSH options "-i" and "-I" for
ignoring paths and drives.
__________________________________________________________________________
CRUSH Options Page 5
____________________________________
-: Set range(s) of dates
DATE OPTIONS. These are used to specify a date range for file
matching. If a single date is specified then this will be the
earliest date to be included. If a second date is specified, then
this is taken as the as the end date. Dates can be mixed in
"absolute" and "relative" format. The full syntax is:
[!]:[=]
Where: ! inverts the meaning of the range set. e.g. "range
1st-2nd" becomes "outside 1st-2nd"
= sets both the start and end date to the date following.
and can be:
Example:
DD/MM/YY absolute UK date 21/2/94
MM/DD/YY absolute US date (CRUSH determines which) 2/21/94
YY/MM/DD absolute JAPAN date ( " ) 94/2/21
DDMonYY absolute date in alternative format 21feb94
DDMon absolute date (current year) 21feb
-DD number of days before current date, OR -3
m-MM number of months OR m-2
y-YY number of years (truncates to 83 years) y-1
.name where date is taken from file/dir "name" .LASTBAC
The four date formats can be mixed, e.g. -:y-2:-5 (or /:y-2:-5)
specifies files created/modified between 2 years and 5 days ago.
-:y-99:5jan will select all files created on or before 5th Jan
(current year). -!:=-1 selects all files except yesterday's. The
".name" option allows compression of files relative to the date and
time of an existing file. The latter feature allows the user to issue
commands such as "compress all files modified/created since last
backup", using commands such as:
CRUSH -:.BACKTAG BACKUP
REM>BACKTAG
The REM>BACKTAG will create an empty file with the current date and
time, so that the next backup will start with the date and time of
that file.
General Examples: (all use the archive name "BACK")
CRUSH -:11feb BACK Compressing files modified/created on or
after February 11th of this year.
CRUSH -:-3 BACK Files modified/created today or during the 3
previous days.
CRUSH -:-0 BACK As above, but today only.
CRUSH -!:y-3 BACK Not files created during the last 3 years.
CRUSH -:m-4:m-3 BACK Will compress files modified/created between
4 and 3 months ago.
__________________________________________________________________________
CRUSH Options Page 6
____________________________________
-x Exclude pathspecs
In programs such as PKZIP and ARJ, the exclusion pathspecs can appear
in any position in the command-line. With CRUSH they MUST appear
AFTER the archive name with the other pathspecs. CRUSH limits the
user to 300 exclusion filespecs.
Examples: (pathspecs are all case-insensitive)
CRUSH BACKUP *.EXE -xTEST*.* *.COM
This will compress all files matching *.EXE and *.COM, but not those
matching TEST*.*. The order of these filespecs is irrelevant.
CRUSH -r BACKUP -xDOC\*.BAK -x*.TMP
This will recurse, searching for files to compress, but excluding
files that match the path and name DOC\*.BAK, or the name *.TMP in
any subdirectory.
CRUSH -r BACKUP [email protected] [email protected]
This will recurse, searching for file to compress, but excluding any
pathspecs in the response files NOTTHIS or ORTHIS.
____________________________________
-y Answer YES to all questions
This will allow CRUSH to compress without pausing for queries, such
as permission to overwrite an existing file.
____________________________________
-z Add CRUSH archive comment
This will prompt the user for an archive comment to add to the CRUSH
file. Ths will be displayed by UNCRUSH when uncrushing or verifying
an archive.
The user can automatically provide a CRUSH comment without the
program pausing for input by using the DOS echo command. e.g.
ECHO My Comment|CRUSH -z BACKUP
which will give the archive the comment "My Comment".
____________________________________
-v Show files for adding without CRUSHing
This will show which files CRUSH would compress without actually
compressing, with a summary at the end. If the output is re-directed
to a file, then the re-directed file will hold a simple list of files
(equivalent to PKZIP option "[email protected]") e.g.
CRUSH -v BACK > LIST Creating a list of matching files
that would be archived.
The archive name specified will be ignored.
__________________________________________________________________________
CRUSH Options Page 7
____________________________________
-n Store files without paths
This allows the user to prevent pathnames from being stored e.g.
CRUSH -n BACKUP MYDOC\*.DOC
would store files matching *.DOC, but without the path MYDOC\.
____________________________________
-Q Query each file to be archived
This allows the user to choose on-line which files are to be included
in the archive e.g.
CRUSH -Qr DOC *.WP
will search recursively (-r) for all files matching *.WP and query
whether each is to be added to the archive. The user has the option
to accept or reject all the remaining files at any point, or to abort
the compression. This option provides an easy way to construct a
response file, e.g. the following expanded example:
CRUSH -Qr DOC *.WP *.TXT > SAVE
would allow the user to select files for compression while also
creating a response file SAVE for future use, e.g. CRUSH DOC @SAVE.
____________________________________
-q QUIET mode, no output
This will run CRUSH without any display output, unless CRUSH needs to
prompt the user with a question (inhibited by -y). This is useful for
instances where CRUSH is called within BAT scripts or from within
another program.
____________________________________
-a Create an additional index
The price paid for creating CRUSH archives is that, although programs
such as PocketD Plus can still browse the contents of the archives,
searching for files inside CRUSH archives would be prohibitively slow
if each CRUSH archive had to be temporarily decompressed whilst
scanning. The -a option will force CRUSH to create an additional
external index with the extension ".CRI". PocketD Plus will use this
for searching (and also browsing) to allow files to be searched or
selected very quickly. This will obviously have an associated disk
space overhead, but this would not be significant on disks with small
cluster sizes (e.g. floppies), or where the CRUSH saving is already
substantial (i.e. more than 10%)
____________________________________
-e Use the existing archive for comparison
This will allow the user to test the compression improvement without
re-creating the original archive for comparison. CRUSH will still
need the files for compression to be available in uncompressed form.
The option -c must also be used. Make sure that the archive to be
compared is not already a CRUSH archive!
__________________________________________________________________________
CRUSH Options Page 8
____________________________________
-C Colour off
This will use whatever colour is currently in use rather than forcing
white on blue. This normally means white on black.
____________________________________
-C Set colour
This will allow the user to override the colour of the bar graph
displayed during compression. "n" is the normal colour attribute in
the range 0 to 7.
____________________________________
-s Minimise temporary disk space (slow!)
CRUSH will normally use about 25% extra temporary disk space when
running with the -f optimise option. If you do not have sufficient
space to run CRUSH with this option, then "-s" will reduce the space
CRUSH uses, but at the cost of a longer compression time. This option
is not recommended for routine use unless you are normally always
short of disk space. CRUSH does not make use of extended or expanded
memory.
____________________________________
-i Control information type
By default, CRUSH will display a bar graph.
If -i1 is specified, a more comprehensive table will be shown
instead, giving more information.
If -i2 is specified, CRUSH will still show a bar graph, but when -c
is selected it will simultaneously plot the file size, archive size
and CRUSH size, rather than just archive and CRUSH. This will allow
all three sizes to be compared, but will give limited resolution of
the difference between just the archive and CRUSH.
Note: CRUSH plots to a resolution of 1 in 114 (using the special half
width character "221")
____________________________________
-2 Set display of times to 24 hour clock
This will force the display of 24 hour clock times instead of 12 hour
during browsing.
__________________________________________________________________________
The UNCRUSH Program Page 9
The UNCRUSH program is used for uncompressing or viewing CRUSH archives.
It requires access to the corresponding uncompressing programs used by the
base archiver e.g. PKUNZIP for PKZIP files and ARJ for ARJ files. Unlike
CRUSH, UNCRUSH is copyrighted FREEWARE. You may use and distribute freely
providing that its intended use is not mis-represented and it is not
modified in any way.
USAGE: UNCRUSH [opts] archive [destination] [pathspecs] [>outfile]
Where:
[opts] These are options that control UNCRUSH's behaviour. e.g. -v
causes CRUSH to display the names of the compressed files
without uncompressing them. These can be grouped together
for brevity or specified one-by-one, e.g.
-ioq is equivalent to: -i -o -q
The user can choose to use "/" in place of "-" for
preference e.g. -i and /i are equivalent.
archive This is the name of the archive to be uncompressed e.g.
BACKUP or BACKUP.001 etc. If no extension is specified,
then UNCRUSH will look for known extensions that use the
specified name in the order CRU, CRI, ZIP, ARJ, LZH, ZOO,
HA then UC2. UNCRUSH cannot uncompress files with
non-standard extensions. Such files will need to be
re-named before using UNCRUSH, or uncompressed first using
PKUNZIP etc.
[destination] This is the destination path where files are to be
uncompressed. This must be terminated by ":" or "\" to
allow it to be distinguished from normal pathspecs (same
operation as PKUNZIP). Paths within the archive will be
combined with any specified destination path, e.g.
CRUSH BACKUP \WP\*.DOC followed by:
UNCRUSH BACKUP MYDOC\HOME\
will uncompress to MYDOC\HOME\WP\*.DOC
[pathspecs] These are the files to be uncompressed (defaulting to all
files). These can include paths e.g.
UNCRUSH SAVE \WP\*.DOC *.TXT
This will uncompress pathspecs from SAVE matching \WP\*.DOC
and any pathspecs with the filespec *.TXT. i.e. *.TXT will
match *.TXT and \WP\*.TXT, but \WP\*.DOC would not match
*.DOC. UNCRUSH can be set to optionally ignore stored
pathnames. As with CRUSH, UNCRUSH uses proper rather than
DOS wildcards (See CRUSH for details).
[>outfile] UNCRUSH will allow the user to create response or summary
files using re-directed output. See -v, -V and -l.
__________________________________________________________________________
UNCRUSH Options: Page 10
____________________________________
-v Display without uncompressing
This will cause UNCRUSH to report the pathspecs inside the archive
without uncompressing. This gives a sorted output reporting size,
date and time of the file stored. Attributes are not displayed, even
though stored.
____________________________________
-V Display archive comment only
This will simply display the archive comment and the name of the
archive. This is useful for cataloging purposes, allowing this
information to be appended to a reference file e.g.
UNCRUSH -V FRED >> REFFILE
____________________________________
-o Overwrite files without query
This will force UNCRUSH to overwrite files regardless of whether the
file already exists. UNCRUSH would normally inform the user if files
already exist with an option to skip or overwrite the file. UNCRUSH
helpfully also informs the user whether the file to be overwritten is
NEWER, OLDER, IDENTICAL or SAME DATE, DIFFERENT SIZE.
____________________________________
-u Uncompress NEWER or NEW files
This will only uncompress NEW or NEWER files from within the archive.
This will still prompt for overwrites, unless -o is also specified.
____________________________________
-a Uncompress NEW files
This will only uncompress NEW files.
____________________________________
-i Ignore paths in CRUSH file
This will ignore all paths inside the archive, therefore possibly
generating an overwrite warning if WP\FRED.DOC and \DOC2\FRED.DOC
exist in the same CRUSH file.
____________________________________
-I Only ignore drives in paths
As "-i", but only ignoring drive names stored in the CRUSH file. This
accommodates situations where a CRUSH command such as:
CRUSH BACKUP S:\WP\*.DOC
is run, storing a network drive letter with the path. A user on a
non-networked PC would then be unable to uncompress the CRUSH file
without losing the path. The -I option allows this to be overridden.
__________________________________________________________________________
UNCRUSH Options Page 11
____________________________________
-q Quiet mode: No output at all
This will inhibit all output from UNCRUSH, except where UNCRUSH
queries an overwrite.
____________________________________
-z Only suppress output of archiver
This will only suppress the output of the unarchiver run by UNCRUSH.
e.g. UNCRUSH may call PKUNZIP which normally displays information
while uncompressing. This option will inhibit this. This may not
always be safe if the unarchiver has an unusual problem, in which
case the error message the archiver displays will not be visible.
____________________________________
-e Extract even if not CRUSH archive
This is convenient if the user wants to use UNCRUSH to process any
archives, whether CRUSH or not. This will support any pathspecs
given, but will not support specified destination directories.
____________________________________
-l Only display a simple file list
This will replace the normal display by a simple list of files and
pathnames. This is most usefully used with -v to generate a response
file.
____________________________________
-2 Display times as 24-hour clock
This is only a cosmetic detail, but many users are firmly committed
to 12 or 24 hour clocks, in which case UNCRUSH will allow the default
12 hour clock file times to be replaced by a 24 hour clock times.
__________________________________________________________________________
Worked Examples Page 12
There are many routine archiving tasks that CRUSH could be used for. The
following selects a few that either take particular advantage of CRUSH
facilities, or that may be particularly relevant when first using CRUSH.
For simple examples see "Getting Started" at the beginning of this manual.
____________________________________
Generating a Response File for Future Backups
Most archivers allow the user to use a "response" file containing file and
path specifications to be used in addition to (or instead of) CRUSH
command-line parameters. This is convenient when a list is very large.
CRUSH allows the user to choose files for archiving on-line using the -Q
option. e.g.
CRUSH -rQv TEST *.C *.ASM >RESPLIST
This will search all subdirectories (-r), querying each file found (-Q),
but without actually creating an archive (-v). The output is directed to
the file RESPLIST. The user can then use this for future CRUSH archiving
in a command of the form:
CRUSH BACKUP @RESPLIST
____________________________________
Performing Archival Backups
CRUSH's option to backup files dated on or after a named file (not
supported by PKZIP etc.) makes it possible to create backups of all files
modified since the previous backup. This can be combined with CRUSH's
ability to automatically generate a unique filename, as follows:
BACK.BAT containing:
CRUSH -r:.LASTBAC [] *.DOC *.C *.H
IF ERRORLEVEL 1 ECHO Error occurred!
IF ERRORLEVEL 1 GOTO EXIT
REM>LASTBAC
:EXIT
The "[]" parameter replaces the normal archive name by a unique name
generated using the current date and time (e.g. 1CD29E33.ZIP, which uses
the hexadecimal value of the combined 32-bit date and time). CRUSH will
then search all subdirectories for all files matching *.DOC *.C or *.H
modified since the date and time of the file LASTBAC and add them to the
archive. If the archive step fails (e.g. out of memory etc.), the error is
reported and the command sequence ended. If successful, then "REM>LASTBAC"
will create an empty file with the current date and time for reference by
the next backup.
On the next occasion that the command "BACK" is run, CRUSH will only
search for files modified since the last backup.
__________________________________________________________________________
Worked Examples Page 13
____________________________________
Converting all Existing Archives to CRUSH
This would be a potentially mammoth task that would benefit from some
automation, unless you are willing to convert each file one-by-one. A good
choice for this task would be PocketD Plus v4.1 (D.EXE), as follows:
MD TMP
CD TMP
D .ZIP/W[PKUNZIP -d $w//CRUSH -ert $w//PAUSE//D /zd]Rq
This example converts ZIP files by running a command sequence of the
following type for each archive found:
PKUNZIP -d \C\BATS.ZIP Uncompress with subdirectories into TMP.
CRUSH -ert \C\BATS.ZIP (See below).
PAUSE Allow inspection of result.
D /zd Delete uncompressed files/dirs from TMP.
The CRUSH command compares the new CRUSH archive with the existing archive
(-e), but will not replace it unless the new archive is at least 5%
smaller (-t). The files originally compressed may also include paths, and
so CRUSH uses -r to search all uncompressed subdirectories created by the
"PKUNZIP -d" command. For those with a cautious disposition, the D.EXE
command-line includes the "q" option, allowing the user to confirm or
select each archive to be processed. The PAUSE command allows the user to
examine the output of CRUSH before the command "D /zd" deletes the files
and subdirectories temporarily uncompressed.
____________________________________
The UNDO and UNDO2 Programs
The registered version of CRUSH.EXE comes with two additional programs,
UNDO.EXE and UNDO2.EXE, which provide tiny alternatives to UNCRUSH.EXE for
unpacking an uncompressed CRUSH archive.
USAGE: UNDO crushname
UNDO2 crushname
UNDO.EXE is 3.8k and ignores any path information. UNDO2.EXE is 4.3k and
will also re-construct embedded paths. These programs can be included
within distribution archives that hold CRUSH archives, providing the
smallest package that will allow UNCRUSHing without additional programs.
Ideally UNDO.EXE and a CRU archive could be embedded inside an SFX
archive, e.g. using LHA:
CRUSH -l DEMO ! *.DOC
LHA A DEMO UNDO.EXE
LHA S DEMO
The "!" parameter above is the file "!" which contains a message displayed
when the archive DEMO.EXE is run. This can contain details of how to
uncompress the CRUSH archive, e.g. "Unpack the CRUSH archive by typing
UNDO DEMO.CRU after the DEMO.EXE executable has finished decompression."
The user may choose to rename UNDO2.EXE to UNDO.EXE or some other
convenient name. Note that distribution of CRUSH archives requires a
distribution licence (see REGISTER.DOC).
__________________________________________________________________________
Configuration Page 14
__________________________________
Configuration of CRUSH and UNCRUSH
CRUSH and UNCRUSH can be configured using environment variables, as
follows:
The CRUSH variable:
This is particularly important if you decide not to use the default
PKZIP used by CRUSH e.g.
SET CRUSH=-j
will force CRUSH to always use ARJ by default. Other options can also
be added e.g.
SET CRUSH=-jCc
will also force the normal display colour and always force a
comparison between ARJ and CRUSH when creating a CRUSH file.
The UNCRUSH variable:
This is less critical, but an example usage might be:
SET UNCRUSH=-2e
which would use the 24 hour clock and also allow UNCRUSH to be used
for uncompressing ordinary PKZIP, ARJ, LHA, ZOO, HA and UC archives.
Environment variables should be set in your AUTOEXEC.BAT, otherwise they
will be lost next time the system is re-booted.
__________________________________________________________________________
Technical Details Page 15
This information is only of interest to 3rd party developers who may want
to provide support for CRUSH archives.
__________________________________
Structure of CRUSH file (.CRU)
Address Length in Bytes Description
000000 14 CRUSH v1.3
00000E 2 Chksum
000010 2 Number of paths (only 0-255 supported)
000012 2 Number of files
000014 2 Reserved
000016 4 Totalsize of files + header length(26)
00001A "totalsize" Data
; directory held at offset "Totalsize of files + header length(26)"
000000 1 Path number
000001 1 Attribute
000002 2 Time
000004 2 Date
000006 4 Size
00000A 13 Name
000017 1 Reserved
(above repeated "Number of files" times)
; "n" Paths
path1 Each terminated by NULL
path2
..
; Archive comment
comment Terminated by NULL
__________________________________
Structure of CRUSH fast Index (.CRI)
As CRU but with Totalsize field set to 0 + Headerlen(26)
000016 4 Header length(26)
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
__________________________________________________________________________
CRUSH v1.3 Readme File
__________________________________________________________________________
CRUSH is a new shareware product from the same author as the awarding
winning DOS file manager PocketD Plus ("BEST UTILITY 1992" PsL and joint
runner-up WHAT PC's "BEST UTILITY 1994" with Stacker v4.0 & Dr Solomon's
Virus Toolkit). PocketD Plus has been upgraded to v4.1 to support CRUSH.
>>>>>>>> WHAT IS CRUSH ?
CRUSH is a compression tool that can work with your existing archiver
to dramatically reduce the size of archives created. In many
instances CRUSH achieves an average 2:1 advantage over PKZIP and 8:1
over uncompressed files. However CRUSH is neither slow nor
inconvenient to use. The command-line syntax is essentially similar
to PKZIP, but with many powerful extensions.
CRUSH will work with any of PKZIP, ARJ, LHA, ZOO, UC2 and HA. The
archivers PKZIP, UC2 and ARJ are Shareware and require registration
payments. LHA, ZOO and HA are Copyrighted Freeware.
>>>>>>>> HOW DOES IT WORK ?
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will
generally compress better than small files, a property used by Unix
users who follow the maxim "always tar before compress" (joining
files together before compressing). CRUSH will automatically do this
for you, generating a single file with an extension "CRU" that it
compresses using your chosen archiver (default PKZIP). Extraction of
files is then very easy: UNCRUSH works in the same way as PKUNZIP.
CRUSH gets the most from this compression trick by taking it one step
further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to
recognise 7 different compressed header types), and orders them
accordingly. This yields a very good default fast compression.
Given more time CRUSH can do better by optionally performing a series
of trials to squeeze out extra compression. The algorithm for this
uses an intelligent re-ordering mechanism which analyses the results
of each intermediate test in order to determine which ordering to try
next. This was developed over a period of 2 years where it was
successfully used to reduce the file size of PocketD Plus to the
absolute minimum. This technique allows CRUSH to find near optimum
compression in a few minutes that might take hundreds of years using
more brute-force methods!
>>>>>>>> HOW GOOD IS IT?
Using CRUSH would not be worthwhile if it yielded a narrow advantage
over existing archivers, but in many situations it is capable of
delivering dramatically better compression. The results below are
genuine random tests performed on files taken from a 250-user PC
server and from a publically available CD-ROM.
All archivers were run with maximum compression, except CRUSH which
was set to minimum. The figures for Stacker and DoubleSpace are
commercially quoted performance figures for comparison, not test
results. All the figures quote the compression ratio in terms of disk
space used rather than actual file sizes (8k cluster assumed) to
allow comparison with Stacker 4.0. This does not significantly affect
the comparison between the other archivers (Figures for ZOO are not
quoted as it uses the same compression algorithm as LHA. Figures for
UC2 are not quoted as support for this has only just been added).
>>>>>>>> (1) CRUSH at its BEST -- Working with small data files
CRUSH works best with collections of similar small files. In a block test
of 128 directories (each compressed to its own archive) containing 2349
wordprocessing files (total 33 Megabytes), CRUSH with minimum optimisation
generated the following average compression ratio, calculated by:
Ratio = (disk space used by uncompressed files)/(space after compression)
Ratio
CRUSH+HA 7.95
CRUSH+PKZIP 7.82
CRUSH+ARJ 6.16
CRUSH+LHA 5.46
HA 0.98 4.32
PKZIP 2.04g 4.11
ARJ 2.3 4.18
LHA 2.11 4.12
Stacker 4.0 2.50
DoubleSpace 1.90
Orig Files 1.00
CRUSH clearly yields a substantial improvement in all cases. Its worst
result is with LHA, but this is still much better than any non-CRUSH
compression.
>>>>>>>> HOW FAST IS CRUSH ?
These results might be of limited value if the cost in time for
compression was great. The chart below shows the compression times for 6
wordprocessing files, totalling 150k on a 486SX25 with a ramdrive:
Seconds
CRUSH+HA 11.04
CRUSH+ZIP 3.51
CRUSH+ARJ 3.30
CRUSH+LHA 3.68
CRUSH+ZOO 8.57
HA 0.98 10.98
PKZIP 2.04 2.26
ARJ 2.3 3.02
LHA 2.11 3.30
ZOO 2.1 7.85
From these compression and speed results it can be seem that CRUSH with HA
0.98 offers the best overall compression, but that CRUSH with PKZIP or ARJ
does nearly as well, but are both over 3 times faster.
>>>>>>>> (2) CRUSH at its WORST -- Working with large or dissimilar files
CRUSH has the most difficulty when given large or dissimilar files. A good
example of this might be a Shareware release file which contains a mixture
of documents, executable and other files. A test with minimum optimisation
on 40 random archive files from the ASP-CD ROM (17 Megabytes) yielded the
following results:
Ratio
CRUSH+HA 2.84
CRUSH+ZIP 2.80
HA 0.98 2.76
PKZIP 2.04g 2.70
ARJ 2.3 2.70
LHA 2.11 2.66
Stacker 4.0 (2.50)
Doublespace (1.90)
Orig Files 1.00
Here, improved performance is somewhat less than the previous example,
corresponding to a 3.7% improvement with PKZIP. Many of the compressions
yielded a 0% improvement because although the newly compressed file may
have been smaller, it still occupied the same number of disk allocation
units (clusters). The average improvement in actual file size (important
for file downloads) was 5.6% for PKZIP, with a low of 1% and high of 28%.
The figures for Stacker and DoubleSpace are bracketed as they almost
certainly greatly overestimate their performances in these cases.
>>>>>>>> I USE STACKER. IS THERE MERIT IN USING CRUSH ?
On the fly compression provided by products such as Stacker offers
convenient but low performance compression. Stacker may make your 100 Mb
drive look like 250 Mb, but CRUSH may make it look like 800 Mb. On the fly
compression also has performance penalties and there is a question mark
over its safety.
Of course, CRUSH can safely be used in conjunction with Stacker to obtain
the highest possible net space saving.
>>>>>>>> IS IT WORTH MY WHILE USING CRUSH ?
If your PC is loaded with applications, but little data, then CRUSH may
not help that much. If your PC or PC server typically holds many source
files, database files or wordprocessing documents, then the advantages
might be enormous. A beta test site for CRUSH had vast numbers of
wordprocessing files for which CRUSH was able to achieve a compression
ratio of 16:1 where PKZIP had only yielded 6:1.
>>>>>>>> ARE THERE ANY DRAWBACKS IN USING CRUSH ?
CRUSH requires a significant quantity of temporary filespace whilst
compressing. In the default mode it will typically need 3.0 Mb of
temporary disk space available in order to compress 2.0 Mb of files. The
same is true when uncompressing. To extract a single 1k file from an
archive that contains 1 Mb will require 1 Mb of temporary file space.
CRUSH will not allow the user to update a single file or group of files
within a CRUSH archive. The entire archive must be re-created. It will
therefore be less useful to users who want to regularly update the same
archive to reflect frequent changes.
CRUSH is new and therefore many 3rd party programs will not yet be able to
search or view CRUSHed files. However these will appear, and the very
capable PocketD Plus v4.1 can already do this, allowing viewing of files
inside CRUSH archives with the same ease as any other archive type.
>>>>>>>> ARE THERE ANY OTHER ADVANTAGES IN USING CRUSH ?
CRUSH supports features such as recursive directory searching, storing of
paths, archive comments, file inclusion/exclusion by name and date, as
other archivers. However CRUSH also adds its own special facilities.
1. On-line Selection of Files
CRUSH allows the user to select files for archiving from an on-line
prompt, rather than forcing files to be always explicitly specified
in the command-line. This allows the user to issue commands such as
"Search the drive for files matching *.C modified during the last 6
days and present each matching name for acceptance or rejection".
2. Automatic Archive Name Generation
CRUSH has an option to automatically generate unique archive names
based on the current date and time. This is an ideal mechanism for
creating multiple generation backups.
3. Relative and Backup Date Testing
Unlike programs such as ARJ and PKZIP, CRUSH allows relative dates to
be specified, e.g. "CRUSH -r:-4 BACKUP" will search for and compress
files modified today or during the previous 4 days. CRUSH also allows
a "compress-since-last-backup" feature by allowing the comparison
with a named file date and time, e.g. "CRUSH -:.LASTBAC BACKUP" will
compress files modified since the date and time of the file LASTBAC.
4. Safer Decompression
UNCRUSH will helpfully tell you that a file to be de-compressed
already exists, and also if it is older, newer or identical.
5. CRUSH Supports Proper Wildcards
Unlike DOS (and PKZIP etc.), CRUSH supports proper wildcards. e.g.
the DOS wildcard *FRED.* would match a file called JOE! CRUSH
correctly implements "*" as any sequence of characters (including
none) and "?" as a single character.
6. User-specified Thresholds
CRUSH can be set to create a conventional archive where it cannot
improve by a specified percentage improved compression.
>>>>>>>> HOW DO I COMPARE CRUSH AND PKZIP (OR OTHER) PERFORMANCE ?
CRUSH has a convenient option "-c" which will run the chosen archiver
as well as performing a CRUSH archive operation. The results of this
are displayed as a bar graph (or table, if required).
>>>>>>>> HOW MUCH EXTRA WILL MAXIMUM CRUSH COMPRESSION GIVE ?
The cost in time for turning on extra optimisation in CRUSH is large.
Adding the -f option will probably increase compression time by a
factor of 5-10 times the default minimum, probably yielding between
1%-10% extra compression. However if you want to compress to the
minimum, then you may be happy to leave it overnight with -f200!
_________________________________
CRUSH v1.3
**** Shareware Manual ****
__________________________________
File Compression Tool
CRUSH (TM) Copyright Jeff Rollason, PocketWare (TM) 1994
All Rights Reserved
All Trademarks Are Acknowledged
No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated
into any other language in whole or in part, in any form or
by any means, whether it be electronic, mechanical,
magnetic, optical, manual or otherwise, without prior
written consent of PocketWare.
PocketWare PO Box 2369, Hendon, London NW4 1NR, England.
CIS 100031,3537. Internet [email protected]
__________________________________________________________________________
Contents:
CONTENTS: Page
Getting Started: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The CRUSH program: . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Default use of PKZIP . . . . . . . . . . . . . . . . . . . . . . . 3
-j Use ARJ . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-o Use ZOO . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-l Use LHA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-h Use HA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-u Use UC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-m Moves file to archive . . . . . . . . . . . . . . . . . . . . 3
-c Compare with and without CRUSH . . . . . . . . . . . . . . . 3
-f Optimise until 5 failed attempts to improve compression . . . 4
-f
-t Only create CRUSH archive if 5% improvement . . . . . . . . . 4
-t
-r Recurse subdirectories . . . . . . . . . . . . . . . . . . . 4
-: Set range(s) of dates . . . . . . . . . . . . . . . . . . . . 5
-x Exclude pathspecs . . . . . . . . . . . . . . . . . . . . . . 6
-y Answer YES to all questions . . . . . . . . . . . . . . . . . 6
-z Add CRUSH archive comment . . . . . . . . . . . . . . . . . . 6
-v Show files for adding without CRUSHing . . . . . . . . . . . 6
-n Store files without paths . . . . . . . . . . . . . . . . . . 7
-Q Query each file to be archived. . . . . . . . . . . . . . . . 7
-q QUIET mode, no output . . . . . . . . . . . . . . . . . . . . 7
-a Create an additional index . . . . . . . . . . . . . . . . . 7
-e Use the existing archive for comparison . . . . . . . . . . . 7
-C Colour off . . . . . . . . . . . . . . . . . . . . . . . . . 8
-C
-s Minimise temporary disk space (slow!) . . . . . . . . . . . . 8
-i
-2 Set display of times to 24 hour clock . . . . . . . . . . . . 8
The UNCRUSH Program: . . . . . . . . . . . . . . . . . . . . . . . . . . 9
-v Display without uncompressing . . . . . . . . . . . . . . . .10
-V Display archive comment only . . . . . . . . . . . . . . . .10
-o Overwrite files without query . . . . . . . . . . . . . . . .10
-u Uncompress NEWER or NEW files . . . . . . . . . . . . . . . .10
-a Uncompress NEW files . . . . . . . . . . . . . . . . . . . .10
-i Ignore paths in CRUSH file . . . . . . . . . . . . . . . . .10
-I Only ignore drives in paths . . . . . . . . . . . . . . . . .10
-q Quiet mode: No output at all . . . . . . . . . . . . . . . .11
-z Only suppress output of archiver . . . . . . . . . . . . . .11
-e Extract even if not CRUSH archive . . . . . . . . . . . . . .11
-l Only display a simple file list . . . . . . . . . . . . . . .11
-2 Display times as 24-hour clock . . . . . . . . . . . . . . .11
Worked Examples: . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
The UNDO and UNDO2 Programs: . . . . . . . . . . . . . . . . . . . . . .13
Configuration: . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Technical Details: . . . . . . . . . . . . . . . . . . . . . . . . . . .15
_________________________________________________________________________
Getting Started Page 1
____________________________________
Installation
CRUSH installation is very simple. The user need only copy the contents of
the release disk to the desired directory. A file INSTALL.BAT is provided
to do this for you. Your chosen directory should be within your search
path (See the PATH variable in your DOS documentation).
In order to be able to use CRUSH, you must have one of the archivers
PKZIP, ARJ, LHA, ZOO, HA and UC.
____________________________________
What is CRUSH?
CRUSH is a command-line tool that uses your existing archiver PKZIP, ARJ,
LHA, ZOO, HA or UC to generate smaller archives than it could alone. With
many applications this improvement may be less than 5%, but dramatic
improvements of 10%-70% are much more typical. A block test of 128
archives totalling 2349 wordprocessing files (see README) averaged a 47%
improvement (100k ZIP reduced to 53k CRUSH!). CRUSH is ideally suited to
users who regularly archive material or who just need to save disk space.
There is no other compression tool for DOS (as of June 1994) that can
match the compression performance of CRUSH, and most do not come close.
____________________________________
CRUSH and other Archivers
CRUSH is used from the command-line in much the same way as archivers such
as PKZIP and ARJ. If you are already familiar with these, then you should
be able to adapt to CRUSH with very little difficulty. If you are a ZOO,
LHA or HA user, then you will observe some changes, but will find the
basic operation of CRUSH very similar.
____________________________________
Simple use of CRUSH
To create a CRUSH archive called BACKUP containing all the files in the
current directory requires the following simple command:
CRUSH BACKUP
This will create the file BACKUP.ZIP (PKZIP must be available). The user
can be more selective by adding filespecs, as follows:
CRUSH BACKUP *.DOC README MAN*.*
This will only save files with the specified filespecs. The user may also
want to receive some feedback about how much space is being saved. The
"-c" (compare) option will allow a comparison to be made:
CRUSH -c BACKUP *.DOC README MAN*.*
Once created, a CRUSH archive can be uncompressed using UNCRUSH in much
the same way as PKUNZIP is used. e.g. UNCRUSH BACKUP *.DOC. This only
extracts files matching *.DOC. The user is advised to read the "Worked
Examples" section for more details of CRUSH usage, and also the README
file. Simply type "CRUSH" to obtain on-line help.
_________________________________________________________________________
The CRUSH program Page 2
This is the program that will replace the use of PKZIP, LHA, ARJ, ZOO, HA
and UC. Whichever of these you already use will still be needed, but CRUSH
will run it for you. The command-line syntax of CRUSH is, for most cases,
identical to PKZIP usage. CRUSH preserves dates, times and attributes.
USAGE: CRUSH [opts] archive [pathspecs] [@lists] [>outfile]
Where:
[opts] These are options that control CRUSH's behaviour. e.g. -r
causes CRUSH to search subdirectories. These can be grouped
together for brevity or specified one-by-one, e.g.
-rca is equivalent to: -r -c -a
The user can choose to use "/" in place of "-" for
preference. e.g. -r and /r are equivalent.
archive This is the name of the archive to be created e.g. BACKUP
or BACKUP.001 etc. If no extension is specified, then the
default extension for the archiver used will be adopted
(default PKZIP). If the special name "[]" is given (e.g.
CRUSH []), then CRUSH will generate a unique archive name
based on the current date and time (assuming that archives
are not created within 2 seconds of each other).
[pathspecs] These are the files to be compressed (defaulting to all
files in the current directory). e.g.
CRUSH SAVE \WP\*.DOC *.TXT
This will compress into SAVE.ZIP all files matching *.DOC
from the directory \WP and all files matching *.TXT from
the current directory. The path \WP\ will also be stored in
the archive, to be re-created by UNCRUSH. UNCRUSH can
optionally ignore stored pathnames.
CRUSH uses proper rather than DOS wildcards. e.g. the DOS
wildcard *FRED.* will match a file called JOE because
*FRED.* and *.* are treated by DOS as equivalent. CRUSH
interprets "*" as any sequence of characters, including
zero length. See also the "-x" EXCLUSION filespecs.
[@lists] CRUSH will accept response files containing lists of files
to be processed. These should contain one pathspec per line
and can contain comments starting with ";" e.g.
*.EXE
\WP\*.DOC ; save my docs
; Fred's stuff here onwards
\BIN\*.EXE
Unlike PKZIP, the response file can be of any length (PKZIP
limits the user to 500 filespecs).
[>outfile] CRUSH can generate a response file by re-directing the
output to a file for later use e.g. CRUSH DOCS >SAVE
__________________________________________________________________________
CRUSH Options Page 3
CRUSH will default to using PKZIP unless -j, -o, -l, -h or -u is
specified. PKZIP is the world's best known archiver, written by Paul Katz
and marketed as Shareware by PKWARE. CRUSH will work with any version of
PKZIP, but the user is recommended to use PKZIP v2.04 or later, which
achieves significantly better compression than v1.x.
____________________________________
-j Use ARJ
This instructs CRUSH to use Robert K Jung's "ARJ" program instead of
PKZIP. This can be specified as a general default using the CRUSH
environment variable e.g. SET CRUSH=-j
Example:
CRUSH BACKUP Use PKZIP
CRUSH -j BACKUP Use ARJ
____________________________________
-o Use ZOO
This will use the ZOO program, creating ZOO files.
____________________________________
-l Use LHA
This will use Haruyasu Yoshizaki's "LHA" program, creating LZH files.
____________________________________
-h Use HA
This will use Harri Hirvola's "HA" program, creating HA files. HA
produces very small archives, but is quite slow.
____________________________________
-u Use UC2
This uses Ad Infinitum Programs's "UC" program. This uses a great of
DOS memory and will probably require the added program US.EXE to
allow CRUSH access to the 80k it needs. e.g. US CRUSH -u SAVE
____________________________________
-m Moves file to archive
This will delete the original files after they have been successfully
compressed.
____________________________________
-c Compare with and without CRUSH
This allows CRUSH to show how much filespace has been saved over the
archiver alone. This will make CRUSH slower as an additional
compression is needed in order to make a comparison (unless -e is
also used). The results are displayed as a bar graph, plotting
archive and CRUSH sizes. The original file size can also be plotted
by adding the option -i2.
__________________________________________________________________________
CRUSH Options Page 4
____________________________________
-f Optimise until 5 failed attempts to improve compression
This will make CRUSH experiment with different orderings to improve
the compression. CRUSH will end when it has failed 5 times to find an
improvement. This will increase the run time of CRUSH by at least 5
times. Each time it provides an improvement, the time taken
increases. CRUSH is unlikely to take more than 15 times the normal
compress time.
The results of this trial are displayed as two bar graphs, showing
the size of the first and best CRUSH compression. (See option "-s").
____________________________________
-f
As "-f", but allowing the user to specify how long CRUSH is to
continue the trial before giving up e.g.
CRUSH -f2 BACKUP will give up after only 2 failures.
CRUSH -f100 BACKUP will give up after 100 failures.
____________________________________
-t Only create CRUSH archive if 5% improvement
This creates a CRUSH archive only if it can improve the archive size
by 5%, otherwise it creates a conventional archive. It invokes the -c
option, which adds to the run time, as it needs to run the archiver
without CRUSH for comparison.
____________________________________
-t
As "-t", but allowing the user to set the threshold e.g.
CRUSH -t10 BACKUP CRUSH only if 10% better
____________________________________
-r Recurse subdirectories
This will search subdirectories from the specified directories, also
storing paths in the archive. Unlike PKZIP, CRUSH defaults to storing
pathnames with the files. However this is done in a very efficient
manner and so does not significantly increase the archive size (PKZIP
uses a space-consuming format for this e.g. searching a subdirectory
DOCUMENT\MYDOCS with 100 files would require an extra 1660 bytes,
whereas CRUSH would require just 16). Example:
CRUSH -r BACKUP \WP\DOCS\*.WP *.TXT
This will search \WP\DOCS and all its subdirectories for the filespec
*.WP, and the current directory and its subdirectories for *.TXT.
CRUSH will store the full path e.g. \WP\DOCS\HOME\DOC.WP etc.
See also the CRUSH option "-n" and UNCRUSH options "-i" and "-I" for
ignoring paths and drives.
__________________________________________________________________________
CRUSH Options Page 5
____________________________________
-: Set range(s) of dates
DATE OPTIONS. These are used to specify a date range for file
matching. If a single date is specified then this will be the
earliest date to be included. If a second date is specified, then
this is taken as the as the end date. Dates can be mixed in
"absolute" and "relative" format. The full syntax is:
[!]:[=]
Where: ! inverts the meaning of the range set. e.g. "range
1st-2nd" becomes "outside 1st-2nd"
= sets both the start and end date to the date following.
and
Example:
DD/MM/YY absolute UK date 21/2/94
MM/DD/YY absolute US date (CRUSH determines which) 2/21/94
YY/MM/DD absolute JAPAN date ( " ) 94/2/21
DDMonYY absolute date in alternative format 21feb94
DDMon absolute date (current year) 21feb
-DD number of days before current date, OR -3
m-MM number of months OR m-2
y-YY number of years (truncates to 83 years) y-1
.name where date is taken from file/dir "name" .LASTBAC
The four date formats can be mixed, e.g. -:y-2:-5 (or /:y-2:-5)
specifies files created/modified between 2 years and 5 days ago.
-:y-99:5jan will select all files created on or before 5th Jan
(current year). -!:=-1 selects all files except yesterday's. The
".name" option allows compression of files relative to the date and
time of an existing file. The latter feature allows the user to issue
commands such as "compress all files modified/created since last
backup", using commands such as:
CRUSH -:.BACKTAG BACKUP
REM>BACKTAG
The REM>BACKTAG will create an empty file with the current date and
time, so that the next backup will start with the date and time of
that file.
General Examples: (all use the archive name "BACK")
CRUSH -:11feb BACK Compressing files modified/created on or
after February 11th of this year.
CRUSH -:-3 BACK Files modified/created today or during the 3
previous days.
CRUSH -:-0 BACK As above, but today only.
CRUSH -!:y-3 BACK Not files created during the last 3 years.
CRUSH -:m-4:m-3 BACK Will compress files modified/created between
4 and 3 months ago.
__________________________________________________________________________
CRUSH Options Page 6
____________________________________
-x Exclude pathspecs
In programs such as PKZIP and ARJ, the exclusion pathspecs can appear
in any position in the command-line. With CRUSH they MUST appear
AFTER the archive name with the other pathspecs. CRUSH limits the
user to 300 exclusion filespecs.
Examples: (pathspecs are all case-insensitive)
CRUSH BACKUP *.EXE -xTEST*.* *.COM
This will compress all files matching *.EXE and *.COM, but not those
matching TEST*.*. The order of these filespecs is irrelevant.
CRUSH -r BACKUP -xDOC\*.BAK -x*.TMP
This will recurse, searching for files to compress, but excluding
files that match the path and name DOC\*.BAK, or the name *.TMP in
any subdirectory.
CRUSH -r BACKUP [email protected] [email protected]
This will recurse, searching for file to compress, but excluding any
pathspecs in the response files NOTTHIS or ORTHIS.
____________________________________
-y Answer YES to all questions
This will allow CRUSH to compress without pausing for queries, such
as permission to overwrite an existing file.
____________________________________
-z Add CRUSH archive comment
This will prompt the user for an archive comment to add to the CRUSH
file. Ths will be displayed by UNCRUSH when uncrushing or verifying
an archive.
The user can automatically provide a CRUSH comment without the
program pausing for input by using the DOS echo command. e.g.
ECHO My Comment|CRUSH -z BACKUP
which will give the archive the comment "My Comment".
____________________________________
-v Show files for adding without CRUSHing
This will show which files CRUSH would compress without actually
compressing, with a summary at the end. If the output is re-directed
to a file, then the re-directed file will hold a simple list of files
(equivalent to PKZIP option "[email protected]") e.g.
CRUSH -v BACK > LIST Creating a list of matching files
that would be archived.
The archive name specified will be ignored.
__________________________________________________________________________
CRUSH Options Page 7
____________________________________
-n Store files without paths
This allows the user to prevent pathnames from being stored e.g.
CRUSH -n BACKUP MYDOC\*.DOC
would store files matching *.DOC, but without the path MYDOC\.
____________________________________
-Q Query each file to be archived
This allows the user to choose on-line which files are to be included
in the archive e.g.
CRUSH -Qr DOC *.WP
will search recursively (-r) for all files matching *.WP and query
whether each is to be added to the archive. The user has the option
to accept or reject all the remaining files at any point, or to abort
the compression. This option provides an easy way to construct a
response file, e.g. the following expanded example:
CRUSH -Qr DOC *.WP *.TXT > SAVE
would allow the user to select files for compression while also
creating a response file SAVE for future use, e.g. CRUSH DOC @SAVE.
____________________________________
-q QUIET mode, no output
This will run CRUSH without any display output, unless CRUSH needs to
prompt the user with a question (inhibited by -y). This is useful for
instances where CRUSH is called within BAT scripts or from within
another program.
____________________________________
-a Create an additional index
The price paid for creating CRUSH archives is that, although programs
such as PocketD Plus can still browse the contents of the archives,
searching for files inside CRUSH archives would be prohibitively slow
if each CRUSH archive had to be temporarily decompressed whilst
scanning. The -a option will force CRUSH to create an additional
external index with the extension ".CRI". PocketD Plus will use this
for searching (and also browsing) to allow files to be searched or
selected very quickly. This will obviously have an associated disk
space overhead, but this would not be significant on disks with small
cluster sizes (e.g. floppies), or where the CRUSH saving is already
substantial (i.e. more than 10%)
____________________________________
-e Use the existing archive for comparison
This will allow the user to test the compression improvement without
re-creating the original archive for comparison. CRUSH will still
need the files for compression to be available in uncompressed form.
The option -c must also be used. Make sure that the archive to be
compared is not already a CRUSH archive!
__________________________________________________________________________
CRUSH Options Page 8
____________________________________
-C Colour off
This will use whatever colour is currently in use rather than forcing
white on blue. This normally means white on black.
____________________________________
-C
This will allow the user to override the colour of the bar graph
displayed during compression. "n" is the normal colour attribute in
the range 0 to 7.
____________________________________
-s Minimise temporary disk space (slow!)
CRUSH will normally use about 25% extra temporary disk space when
running with the -f optimise option. If you do not have sufficient
space to run CRUSH with this option, then "-s" will reduce the space
CRUSH uses, but at the cost of a longer compression time. This option
is not recommended for routine use unless you are normally always
short of disk space. CRUSH does not make use of extended or expanded
memory.
____________________________________
-i
By default, CRUSH will display a bar graph.
If -i1 is specified, a more comprehensive table will be shown
instead, giving more information.
If -i2 is specified, CRUSH will still show a bar graph, but when -c
is selected it will simultaneously plot the file size, archive size
and CRUSH size, rather than just archive and CRUSH. This will allow
all three sizes to be compared, but will give limited resolution of
the difference between just the archive and CRUSH.
Note: CRUSH plots to a resolution of 1 in 114 (using the special half
width character "221")
____________________________________
-2 Set display of times to 24 hour clock
This will force the display of 24 hour clock times instead of 12 hour
during browsing.
__________________________________________________________________________
The UNCRUSH Program Page 9
The UNCRUSH program is used for uncompressing or viewing CRUSH archives.
It requires access to the corresponding uncompressing programs used by the
base archiver e.g. PKUNZIP for PKZIP files and ARJ for ARJ files. Unlike
CRUSH, UNCRUSH is copyrighted FREEWARE. You may use and distribute freely
providing that its intended use is not mis-represented and it is not
modified in any way.
USAGE: UNCRUSH [opts] archive [destination] [pathspecs] [>outfile]
Where:
[opts] These are options that control UNCRUSH's behaviour. e.g. -v
causes CRUSH to display the names of the compressed files
without uncompressing them. These can be grouped together
for brevity or specified one-by-one, e.g.
-ioq is equivalent to: -i -o -q
The user can choose to use "/" in place of "-" for
preference e.g. -i and /i are equivalent.
archive This is the name of the archive to be uncompressed e.g.
BACKUP or BACKUP.001 etc. If no extension is specified,
then UNCRUSH will look for known extensions that use the
specified name in the order CRU, CRI, ZIP, ARJ, LZH, ZOO,
HA then UC2. UNCRUSH cannot uncompress files with
non-standard extensions. Such files will need to be
re-named before using UNCRUSH, or uncompressed first using
PKUNZIP etc.
[destination] This is the destination path where files are to be
uncompressed. This must be terminated by ":" or "\" to
allow it to be distinguished from normal pathspecs (same
operation as PKUNZIP). Paths within the archive will be
combined with any specified destination path, e.g.
CRUSH BACKUP \WP\*.DOC followed by:
UNCRUSH BACKUP MYDOC\HOME\
will uncompress to MYDOC\HOME\WP\*.DOC
[pathspecs] These are the files to be uncompressed (defaulting to all
files). These can include paths e.g.
UNCRUSH SAVE \WP\*.DOC *.TXT
This will uncompress pathspecs from SAVE matching \WP\*.DOC
and any pathspecs with the filespec *.TXT. i.e. *.TXT will
match *.TXT and \WP\*.TXT, but \WP\*.DOC would not match
*.DOC. UNCRUSH can be set to optionally ignore stored
pathnames. As with CRUSH, UNCRUSH uses proper rather than
DOS wildcards (See CRUSH for details).
[>outfile] UNCRUSH will allow the user to create response or summary
files using re-directed output. See -v, -V and -l.
__________________________________________________________________________
UNCRUSH Options: Page 10
____________________________________
-v Display without uncompressing
This will cause UNCRUSH to report the pathspecs inside the archive
without uncompressing. This gives a sorted output reporting size,
date and time of the file stored. Attributes are not displayed, even
though stored.
____________________________________
-V Display archive comment only
This will simply display the archive comment and the name of the
archive. This is useful for cataloging purposes, allowing this
information to be appended to a reference file e.g.
UNCRUSH -V FRED >> REFFILE
____________________________________
-o Overwrite files without query
This will force UNCRUSH to overwrite files regardless of whether the
file already exists. UNCRUSH would normally inform the user if files
already exist with an option to skip or overwrite the file. UNCRUSH
helpfully also informs the user whether the file to be overwritten is
NEWER, OLDER, IDENTICAL or SAME DATE, DIFFERENT SIZE.
____________________________________
-u Uncompress NEWER or NEW files
This will only uncompress NEW or NEWER files from within the archive.
This will still prompt for overwrites, unless -o is also specified.
____________________________________
-a Uncompress NEW files
This will only uncompress NEW files.
____________________________________
-i Ignore paths in CRUSH file
This will ignore all paths inside the archive, therefore possibly
generating an overwrite warning if WP\FRED.DOC and \DOC2\FRED.DOC
exist in the same CRUSH file.
____________________________________
-I Only ignore drives in paths
As "-i", but only ignoring drive names stored in the CRUSH file. This
accommodates situations where a CRUSH command such as:
CRUSH BACKUP S:\WP\*.DOC
is run, storing a network drive letter with the path. A user on a
non-networked PC would then be unable to uncompress the CRUSH file
without losing the path. The -I option allows this to be overridden.
__________________________________________________________________________
UNCRUSH Options Page 11
____________________________________
-q Quiet mode: No output at all
This will inhibit all output from UNCRUSH, except where UNCRUSH
queries an overwrite.
____________________________________
-z Only suppress output of archiver
This will only suppress the output of the unarchiver run by UNCRUSH.
e.g. UNCRUSH may call PKUNZIP which normally displays information
while uncompressing. This option will inhibit this. This may not
always be safe if the unarchiver has an unusual problem, in which
case the error message the archiver displays will not be visible.
____________________________________
-e Extract even if not CRUSH archive
This is convenient if the user wants to use UNCRUSH to process any
archives, whether CRUSH or not. This will support any pathspecs
given, but will not support specified destination directories.
____________________________________
-l Only display a simple file list
This will replace the normal display by a simple list of files and
pathnames. This is most usefully used with -v to generate a response
file.
____________________________________
-2 Display times as 24-hour clock
This is only a cosmetic detail, but many users are firmly committed
to 12 or 24 hour clocks, in which case UNCRUSH will allow the default
12 hour clock file times to be replaced by a 24 hour clock times.
__________________________________________________________________________
Worked Examples Page 12
There are many routine archiving tasks that CRUSH could be used for. The
following selects a few that either take particular advantage of CRUSH
facilities, or that may be particularly relevant when first using CRUSH.
For simple examples see "Getting Started" at the beginning of this manual.
____________________________________
Generating a Response File for Future Backups
Most archivers allow the user to use a "response" file containing file and
path specifications to be used in addition to (or instead of) CRUSH
command-line parameters. This is convenient when a list is very large.
CRUSH allows the user to choose files for archiving on-line using the -Q
option. e.g.
CRUSH -rQv TEST *.C *.ASM >RESPLIST
This will search all subdirectories (-r), querying each file found (-Q),
but without actually creating an archive (-v). The output is directed to
the file RESPLIST. The user can then use this for future CRUSH archiving
in a command of the form:
CRUSH BACKUP @RESPLIST
____________________________________
Performing Archival Backups
CRUSH's option to backup files dated on or after a named file (not
supported by PKZIP etc.) makes it possible to create backups of all files
modified since the previous backup. This can be combined with CRUSH's
ability to automatically generate a unique filename, as follows:
BACK.BAT containing:
CRUSH -r:.LASTBAC [] *.DOC *.C *.H
IF ERRORLEVEL 1 ECHO Error occurred!
IF ERRORLEVEL 1 GOTO EXIT
REM>LASTBAC
:EXIT
The "[]" parameter replaces the normal archive name by a unique name
generated using the current date and time (e.g. 1CD29E33.ZIP, which uses
the hexadecimal value of the combined 32-bit date and time). CRUSH will
then search all subdirectories for all files matching *.DOC *.C or *.H
modified since the date and time of the file LASTBAC and add them to the
archive. If the archive step fails (e.g. out of memory etc.), the error is
reported and the command sequence ended. If successful, then "REM>LASTBAC"
will create an empty file with the current date and time for reference by
the next backup.
On the next occasion that the command "BACK" is run, CRUSH will only
search for files modified since the last backup.
__________________________________________________________________________
Worked Examples Page 13
____________________________________
Converting all Existing Archives to CRUSH
This would be a potentially mammoth task that would benefit from some
automation, unless you are willing to convert each file one-by-one. A good
choice for this task would be PocketD Plus v4.1 (D.EXE), as follows:
MD TMP
CD TMP
D .ZIP/W[PKUNZIP -d $w//CRUSH -ert $w//PAUSE//D /zd]Rq
This example converts ZIP files by running a command sequence of the
following type for each archive found:
PKUNZIP -d \C\BATS.ZIP Uncompress with subdirectories into TMP.
CRUSH -ert \C\BATS.ZIP (See below).
PAUSE Allow inspection of result.
D /zd Delete uncompressed files/dirs from TMP.
The CRUSH command compares the new CRUSH archive with the existing archive
(-e), but will not replace it unless the new archive is at least 5%
smaller (-t). The files originally compressed may also include paths, and
so CRUSH uses -r to search all uncompressed subdirectories created by the
"PKUNZIP -d" command. For those with a cautious disposition, the D.EXE
command-line includes the "q" option, allowing the user to confirm or
select each archive to be processed. The PAUSE command allows the user to
examine the output of CRUSH before the command "D /zd" deletes the files
and subdirectories temporarily uncompressed.
____________________________________
The UNDO and UNDO2 Programs
The registered version of CRUSH.EXE comes with two additional programs,
UNDO.EXE and UNDO2.EXE, which provide tiny alternatives to UNCRUSH.EXE for
unpacking an uncompressed CRUSH archive.
USAGE: UNDO crushname
UNDO2 crushname
UNDO.EXE is 3.8k and ignores any path information. UNDO2.EXE is 4.3k and
will also re-construct embedded paths. These programs can be included
within distribution archives that hold CRUSH archives, providing the
smallest package that will allow UNCRUSHing without additional programs.
Ideally UNDO.EXE and a CRU archive could be embedded inside an SFX
archive, e.g. using LHA:
CRUSH -l DEMO ! *.DOC
LHA A DEMO UNDO.EXE
LHA S DEMO
The "!" parameter above is the file "!" which contains a message displayed
when the archive DEMO.EXE is run. This can contain details of how to
uncompress the CRUSH archive, e.g. "Unpack the CRUSH archive by typing
UNDO DEMO.CRU after the DEMO.EXE executable has finished decompression."
The user may choose to rename UNDO2.EXE to UNDO.EXE or some other
convenient name. Note that distribution of CRUSH archives requires a
distribution licence (see REGISTER.DOC).
__________________________________________________________________________
Configuration Page 14
__________________________________
Configuration of CRUSH and UNCRUSH
CRUSH and UNCRUSH can be configured using environment variables, as
follows:
The CRUSH variable:
This is particularly important if you decide not to use the default
PKZIP used by CRUSH e.g.
SET CRUSH=-j
will force CRUSH to always use ARJ by default. Other options can also
be added e.g.
SET CRUSH=-jCc
will also force the normal display colour and always force a
comparison between ARJ and CRUSH when creating a CRUSH file.
The UNCRUSH variable:
This is less critical, but an example usage might be:
SET UNCRUSH=-2e
which would use the 24 hour clock and also allow UNCRUSH to be used
for uncompressing ordinary PKZIP, ARJ, LHA, ZOO, HA and UC archives.
Environment variables should be set in your AUTOEXEC.BAT, otherwise they
will be lost next time the system is re-booted.
__________________________________________________________________________
Technical Details Page 15
This information is only of interest to 3rd party developers who may want
to provide support for CRUSH archives.
__________________________________
Structure of CRUSH file (.CRU)
Address Length in Bytes Description
000000 14 CRUSH v1.3
00000E 2 Chksum
000010 2 Number of paths (only 0-255 supported)
000012 2 Number of files
000014 2 Reserved
000016 4 Totalsize of files + header length(26)
00001A "totalsize" Data
; directory held at offset "Totalsize of files + header length(26)"
000000 1 Path number
000001 1 Attribute
000002 2 Time
000004 2 Date
000006 4 Size
00000A 13 Name
000017 1 Reserved
(above repeated "Number of files" times)
; "n" Paths
path1 Each terminated by NULL
path2
..
; Archive comment
comment Terminated by NULL
__________________________________
Structure of CRUSH fast Index (.CRI)
As CRU but with Totalsize field set to 0 + Headerlen(26)
000016 4 Header length(26)
Contents of the README.1ST file
CRUSH v1.3 - Super-compressor for DOS.
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
__________________________________________________________________________
CRUSH v1.3 Readme File
__________________________________________________________________________
CRUSH is a new shareware product from the same author as the awarding
winning DOS file manager PocketD Plus ("BEST UTILITY 1992" PsL and joint
runner-up WHAT PC's "BEST UTILITY 1994" with Stacker v4.0 & Dr Solomon's
Virus Toolkit). PocketD Plus has been upgraded to v4.1 to support CRUSH.
>>>>>>>> WHAT IS CRUSH ?
CRUSH is a compression tool that can work with your existing archiver
to dramatically reduce the size of archives created. In many
instances CRUSH achieves an average 2:1 advantage over PKZIP and 8:1
over uncompressed files. However CRUSH is neither slow nor
inconvenient to use. The command-line syntax is essentially similar
to PKZIP, but with many powerful extensions.
CRUSH will work with any of PKZIP, ARJ, LHA, ZOO, UC2 and HA. The
archivers PKZIP, UC2 and ARJ are Shareware and require registration
payments. LHA, ZOO and HA are Copyrighted Freeware.
>>>>>>>> HOW DOES IT WORK ?
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will
generally compress better than small files, a property used by Unix
users who follow the maxim "always tar before compress" (joining
files together before compressing). CRUSH will automatically do this
for you, generating a single file with an extension "CRU" that it
compresses using your chosen archiver (default PKZIP). Extraction of
files is then very easy: UNCRUSH works in the same way as PKUNZIP.
CRUSH gets the most from this compression trick by taking it one step
further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to
recognise 7 different compressed header types), and orders them
accordingly. This yields a very good default fast compression.
Given more time CRUSH can do better by optionally performing a series
of trials to squeeze out extra compression. The algorithm for this
uses an intelligent re-ordering mechanism which analyses the results
of each intermediate test in order to determine which ordering to try
next. This was developed over a period of 2 years where it was
successfully used to reduce the file size of PocketD Plus to the
absolute minimum. This technique allows CRUSH to find near optimum
compression in a few minutes that might take hundreds of years using
more brute-force methods!
>>>>>>>> HOW GOOD IS IT?
Using CRUSH would not be worthwhile if it yielded a narrow advantage
over existing archivers, but in many situations it is capable of
delivering dramatically better compression. The results below are
genuine random tests performed on files taken from a 250-user PC
server and from a publically available CD-ROM.
All archivers were run with maximum compression, except CRUSH which
was set to minimum. The figures for Stacker and DoubleSpace are
commercially quoted performance figures for comparison, not test
results. All the figures quote the compression ratio in terms of disk
space used rather than actual file sizes (8k cluster assumed) to
allow comparison with Stacker 4.0. This does not significantly affect
the comparison between the other archivers (Figures for ZOO are not
quoted as it uses the same compression algorithm as LHA. Figures for
UC2 are not quoted as support for this has only just been added).
>>>>>>>> (1) CRUSH at its BEST -- Working with small data files
CRUSH works best with collections of similar small files. In a block test
of 128 directories (each compressed to its own archive) containing 2349
wordprocessing files (total 33 Megabytes), CRUSH with minimum optimisation
generated the following average compression ratio, calculated by:
Ratio = (disk space used by uncompressed files)/(space after compression)
Ratio
CRUSH+HA 7.95
CRUSH+PKZIP 7.82
CRUSH+ARJ 6.16
CRUSH+LHA 5.46
HA 0.98 4.32
PKZIP 2.04g 4.11
ARJ 2.3 4.18
LHA 2.11 4.12
Stacker 4.0 2.50
DoubleSpace 1.90
Orig Files 1.00
CRUSH clearly yields a substantial improvement in all cases. Its worst
result is with LHA, but this is still much better than any non-CRUSH
compression.
>>>>>>>> HOW FAST IS CRUSH ?
These results might be of limited value if the cost in time for
compression was great. The chart below shows the compression times for 6
wordprocessing files, totalling 150k on a 486SX25 with a ramdrive:
Seconds
CRUSH+HA 11.04
CRUSH+ZIP 3.51
CRUSH+ARJ 3.30
CRUSH+LHA 3.68
CRUSH+ZOO 8.57
HA 0.98 10.98
PKZIP 2.04 2.26
ARJ 2.3 3.02
LHA 2.11 3.30
ZOO 2.1 7.85
From these compression and speed results it can be seem that CRUSH with HA
0.98 offers the best overall compression, but that CRUSH with PKZIP or ARJ
does nearly as well, but are both over 3 times faster.
>>>>>>>> (2) CRUSH at its WORST -- Working with large or dissimilar files
CRUSH has the most difficulty when given large or dissimilar files. A good
example of this might be a Shareware release file which contains a mixture
of documents, executable and other files. A test with minimum optimisation
on 40 random archive files from the ASP-CD ROM (17 Megabytes) yielded the
following results:
Ratio
CRUSH+HA 2.84
CRUSH+ZIP 2.80
HA 0.98 2.76
PKZIP 2.04g 2.70
ARJ 2.3 2.70
LHA 2.11 2.66
Stacker 4.0 (2.50)
Doublespace (1.90)
Orig Files 1.00
Here, improved performance is somewhat less than the previous example,
corresponding to a 3.7% improvement with PKZIP. Many of the compressions
yielded a 0% improvement because although the newly compressed file may
have been smaller, it still occupied the same number of disk allocation
units (clusters). The average improvement in actual file size (important
for file downloads) was 5.6% for PKZIP, with a low of 1% and high of 28%.
The figures for Stacker and DoubleSpace are bracketed as they almost
certainly greatly overestimate their performances in these cases.
>>>>>>>> I USE STACKER. IS THERE MERIT IN USING CRUSH ?
On the fly compression provided by products such as Stacker offers
convenient but low performance compression. Stacker may make your 100 Mb
drive look like 250 Mb, but CRUSH may make it look like 800 Mb. On the fly
compression also has performance penalties and there is a question mark
over its safety.
Of course, CRUSH can safely be used in conjunction with Stacker to obtain
the highest possible net space saving.
>>>>>>>> IS IT WORTH MY WHILE USING CRUSH ?
If your PC is loaded with applications, but little data, then CRUSH may
not help that much. If your PC or PC server typically holds many source
files, database files or wordprocessing documents, then the advantages
might be enormous. A beta test site for CRUSH had vast numbers of
wordprocessing files for which CRUSH was able to achieve a compression
ratio of 16:1 where PKZIP had only yielded 6:1.
>>>>>>>> ARE THERE ANY DRAWBACKS IN USING CRUSH ?
CRUSH requires a significant quantity of temporary filespace whilst
compressing. In the default mode it will typically need 3.0 Mb of
temporary disk space available in order to compress 2.0 Mb of files. The
same is true when uncompressing. To extract a single 1k file from an
archive that contains 1 Mb will require 1 Mb of temporary file space.
CRUSH will not allow the user to update a single file or group of files
within a CRUSH archive. The entire archive must be re-created. It will
therefore be less useful to users who want to regularly update the same
archive to reflect frequent changes.
CRUSH is new and therefore many 3rd party programs will not yet be able to
search or view CRUSHed files. However these will appear, and the very
capable PocketD Plus v4.1 can already do this, allowing viewing of files
inside CRUSH archives with the same ease as any other archive type.
>>>>>>>> ARE THERE ANY OTHER ADVANTAGES IN USING CRUSH ?
CRUSH supports features such as recursive directory searching, storing of
paths, archive comments, file inclusion/exclusion by name and date, as
other archivers. However CRUSH also adds its own special facilities.
1. On-line Selection of Files
CRUSH allows the user to select files for archiving from an on-line
prompt, rather than forcing files to be always explicitly specified
in the command-line. This allows the user to issue commands such as
"Search the drive for files matching *.C modified during the last 6
days and present each matching name for acceptance or rejection".
2. Automatic Archive Name Generation
CRUSH has an option to automatically generate unique archive names
based on the current date and time. This is an ideal mechanism for
creating multiple generation backups.
3. Relative and Backup Date Testing
Unlike programs such as ARJ and PKZIP, CRUSH allows relative dates to
be specified, e.g. "CRUSH -r:-4 BACKUP" will search for and compress
files modified today or during the previous 4 days. CRUSH also allows
a "compress-since-last-backup" feature by allowing the comparison
with a named file date and time, e.g. "CRUSH -:.LASTBAC BACKUP" will
compress files modified since the date and time of the file LASTBAC.
4. Safer Decompression
UNCRUSH will helpfully tell you that a file to be de-compressed
already exists, and also if it is older, newer or identical.
5. CRUSH Supports Proper Wildcards
Unlike DOS (and PKZIP etc.), CRUSH supports proper wildcards. e.g.
the DOS wildcard *FRED.* would match a file called JOE! CRUSH
correctly implements "*" as any sequence of characters (including
none) and "?" as a single character.
6. User-specified Thresholds
CRUSH can be set to create a conventional archive where it cannot
improve by a specified percentage improved compression.
>>>>>>>> HOW DO I COMPARE CRUSH AND PKZIP (OR OTHER) PERFORMANCE ?
CRUSH has a convenient option "-c" which will run the chosen archiver
as well as performing a CRUSH archive operation. The results of this
are displayed as a bar graph (or table, if required).
>>>>>>>> HOW MUCH EXTRA WILL MAXIMUM CRUSH COMPRESSION GIVE ?
The cost in time for turning on extra optimisation in CRUSH is large.
Adding the -f option will probably increase compression time by a
factor of 5-10 times the default minimum, probably yielding between
1%-10% extra compression. However if you want to compress to the
minimum, then you may be happy to leave it overnight with -f200!
_________________________________
CRUSH v1.3
**** Shareware Manual ****
__________________________________
File Compression Tool
CRUSH (TM) Copyright Jeff Rollason, PocketWare (TM) 1994
All Rights Reserved
All Trademarks Are Acknowledged
No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated
into any other language in whole or in part, in any form or
by any means, whether it be electronic, mechanical,
magnetic, optical, manual or otherwise, without prior
written consent of PocketWare.
PocketWare PO Box 2369, Hendon, London NW4 1NR, England.
CIS 100031,3537. Internet [email protected]
__________________________________________________________________________
Contents:
CONTENTS: Page
Getting Started: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The CRUSH program: . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Default use of PKZIP . . . . . . . . . . . . . . . . . . . . . . . 3
-j Use ARJ . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-o Use ZOO . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-l Use LHA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-h Use HA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-u Use UC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-m Moves file to archive . . . . . . . . . . . . . . . . . . . . 3
-c Compare with and without CRUSH . . . . . . . . . . . . . . . 3
-f Optimise until 5 failed attempts to improve compression . . . 4
-f Optimise until "n" failed attempts to improve compression . . 4
-t Only create CRUSH archive if 5% improvement . . . . . . . . . 4
-t Only create CRUSH archive if "n"% improvement . . . . . . . . 4
-r Recurse subdirectories . . . . . . . . . . . . . . . . . . . 4
-: Set range(s) of dates . . . . . . . . . . . . . . . . . . . . 5
-x Exclude pathspecs . . . . . . . . . . . . . . . . . . . . . . 6
-y Answer YES to all questions . . . . . . . . . . . . . . . . . 6
-z Add CRUSH archive comment . . . . . . . . . . . . . . . . . . 6
-v Show files for adding without CRUSHing . . . . . . . . . . . 6
-n Store files without paths . . . . . . . . . . . . . . . . . . 7
-Q Query each file to be archived. . . . . . . . . . . . . . . . 7
-q QUIET mode, no output . . . . . . . . . . . . . . . . . . . . 7
-a Create an additional index . . . . . . . . . . . . . . . . . 7
-e Use the existing archive for comparison . . . . . . . . . . . 7
-C Colour off . . . . . . . . . . . . . . . . . . . . . . . . . 8
-C Set colour . . . . . . . . . . . . . . . . . . . . . . . . . 8
-s Minimise temporary disk space (slow!) . . . . . . . . . . . . 8
-i Control information type . . . . . . . . . . . . . . . . . . 8
-2 Set display of times to 24 hour clock . . . . . . . . . . . . 8
The UNCRUSH Program: . . . . . . . . . . . . . . . . . . . . . . . . . . 9
-v Display without uncompressing . . . . . . . . . . . . . . . .10
-V Display archive comment only . . . . . . . . . . . . . . . .10
-o Overwrite files without query . . . . . . . . . . . . . . . .10
-u Uncompress NEWER or NEW files . . . . . . . . . . . . . . . .10
-a Uncompress NEW files . . . . . . . . . . . . . . . . . . . .10
-i Ignore paths in CRUSH file . . . . . . . . . . . . . . . . .10
-I Only ignore drives in paths . . . . . . . . . . . . . . . . .10
-q Quiet mode: No output at all . . . . . . . . . . . . . . . .11
-z Only suppress output of archiver . . . . . . . . . . . . . .11
-e Extract even if not CRUSH archive . . . . . . . . . . . . . .11
-l Only display a simple file list . . . . . . . . . . . . . . .11
-2 Display times as 24-hour clock . . . . . . . . . . . . . . .11
Worked Examples: . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
The UNDO and UNDO2 Programs: . . . . . . . . . . . . . . . . . . . . . .13
Configuration: . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Technical Details: . . . . . . . . . . . . . . . . . . . . . . . . . . .15
_________________________________________________________________________
Getting Started Page 1
____________________________________
Installation
CRUSH installation is very simple. The user need only copy the contents of
the release disk to the desired directory. A file INSTALL.BAT is provided
to do this for you. Your chosen directory should be within your search
path (See the PATH variable in your DOS documentation).
In order to be able to use CRUSH, you must have one of the archivers
PKZIP, ARJ, LHA, ZOO, HA and UC.
____________________________________
What is CRUSH?
CRUSH is a command-line tool that uses your existing archiver PKZIP, ARJ,
LHA, ZOO, HA or UC to generate smaller archives than it could alone. With
many applications this improvement may be less than 5%, but dramatic
improvements of 10%-70% are much more typical. A block test of 128
archives totalling 2349 wordprocessing files (see README) averaged a 47%
improvement (100k ZIP reduced to 53k CRUSH!). CRUSH is ideally suited to
users who regularly archive material or who just need to save disk space.
There is no other compression tool for DOS (as of June 1994) that can
match the compression performance of CRUSH, and most do not come close.
____________________________________
CRUSH and other Archivers
CRUSH is used from the command-line in much the same way as archivers such
as PKZIP and ARJ. If you are already familiar with these, then you should
be able to adapt to CRUSH with very little difficulty. If you are a ZOO,
LHA or HA user, then you will observe some changes, but will find the
basic operation of CRUSH very similar.
____________________________________
Simple use of CRUSH
To create a CRUSH archive called BACKUP containing all the files in the
current directory requires the following simple command:
CRUSH BACKUP
This will create the file BACKUP.ZIP (PKZIP must be available). The user
can be more selective by adding filespecs, as follows:
CRUSH BACKUP *.DOC README MAN*.*
This will only save files with the specified filespecs. The user may also
want to receive some feedback about how much space is being saved. The
"-c" (compare) option will allow a comparison to be made:
CRUSH -c BACKUP *.DOC README MAN*.*
Once created, a CRUSH archive can be uncompressed using UNCRUSH in much
the same way as PKUNZIP is used. e.g. UNCRUSH BACKUP *.DOC. This only
extracts files matching *.DOC. The user is advised to read the "Worked
Examples" section for more details of CRUSH usage, and also the README
file. Simply type "CRUSH" to obtain on-line help.
_________________________________________________________________________
The CRUSH program Page 2
This is the program that will replace the use of PKZIP, LHA, ARJ, ZOO, HA
and UC. Whichever of these you already use will still be needed, but CRUSH
will run it for you. The command-line syntax of CRUSH is, for most cases,
identical to PKZIP usage. CRUSH preserves dates, times and attributes.
USAGE: CRUSH [opts] archive [pathspecs] [@lists] [>outfile]
Where:
[opts] These are options that control CRUSH's behaviour. e.g. -r
causes CRUSH to search subdirectories. These can be grouped
together for brevity or specified one-by-one, e.g.
-rca is equivalent to: -r -c -a
The user can choose to use "/" in place of "-" for
preference. e.g. -r and /r are equivalent.
archive This is the name of the archive to be created e.g. BACKUP
or BACKUP.001 etc. If no extension is specified, then the
default extension for the archiver used will be adopted
(default PKZIP). If the special name "[]" is given (e.g.
CRUSH []), then CRUSH will generate a unique archive name
based on the current date and time (assuming that archives
are not created within 2 seconds of each other).
[pathspecs] These are the files to be compressed (defaulting to all
files in the current directory). e.g.
CRUSH SAVE \WP\*.DOC *.TXT
This will compress into SAVE.ZIP all files matching *.DOC
from the directory \WP and all files matching *.TXT from
the current directory. The path \WP\ will also be stored in
the archive, to be re-created by UNCRUSH. UNCRUSH can
optionally ignore stored pathnames.
CRUSH uses proper rather than DOS wildcards. e.g. the DOS
wildcard *FRED.* will match a file called JOE because
*FRED.* and *.* are treated by DOS as equivalent. CRUSH
interprets "*" as any sequence of characters, including
zero length. See also the "-x" EXCLUSION filespecs.
[@lists] CRUSH will accept response files containing lists of files
to be processed. These should contain one pathspec per line
and can contain comments starting with ";" e.g.
*.EXE
\WP\*.DOC ; save my docs
; Fred's stuff here onwards
\BIN\*.EXE
Unlike PKZIP, the response file can be of any length (PKZIP
limits the user to 500 filespecs).
[>outfile] CRUSH can generate a response file by re-directing the
output to a file for later use e.g. CRUSH DOCS >SAVE
__________________________________________________________________________
CRUSH Options Page 3
CRUSH will default to using PKZIP unless -j, -o, -l, -h or -u is
specified. PKZIP is the world's best known archiver, written by Paul Katz
and marketed as Shareware by PKWARE. CRUSH will work with any version of
PKZIP, but the user is recommended to use PKZIP v2.04 or later, which
achieves significantly better compression than v1.x.
____________________________________
-j Use ARJ
This instructs CRUSH to use Robert K Jung's "ARJ" program instead of
PKZIP. This can be specified as a general default using the CRUSH
environment variable e.g. SET CRUSH=-j
Example:
CRUSH BACKUP Use PKZIP
CRUSH -j BACKUP Use ARJ
____________________________________
-o Use ZOO
This will use the ZOO program, creating ZOO files.
____________________________________
-l Use LHA
This will use Haruyasu Yoshizaki's "LHA" program, creating LZH files.
____________________________________
-h Use HA
This will use Harri Hirvola's "HA" program, creating HA files. HA
produces very small archives, but is quite slow.
____________________________________
-u Use UC2
This uses Ad Infinitum Programs's "UC" program. This uses a great of
DOS memory and will probably require the added program US.EXE to
allow CRUSH access to the 80k it needs. e.g. US CRUSH -u SAVE
____________________________________
-m Moves file to archive
This will delete the original files after they have been successfully
compressed.
____________________________________
-c Compare with and without CRUSH
This allows CRUSH to show how much filespace has been saved over the
archiver alone. This will make CRUSH slower as an additional
compression is needed in order to make a comparison (unless -e is
also used). The results are displayed as a bar graph, plotting
archive and CRUSH sizes. The original file size can also be plotted
by adding the option -i2.
__________________________________________________________________________
CRUSH Options Page 4
____________________________________
-f Optimise until 5 failed attempts to improve compression
This will make CRUSH experiment with different orderings to improve
the compression. CRUSH will end when it has failed 5 times to find an
improvement. This will increase the run time of CRUSH by at least 5
times. Each time it provides an improvement, the time taken
increases. CRUSH is unlikely to take more than 15 times the normal
compress time.
The results of this trial are displayed as two bar graphs, showing
the size of the first and best CRUSH compression. (See option "-s").
____________________________________
-f Optimise until "n" failed attempts to improve compression
As "-f", but allowing the user to specify how long CRUSH is to
continue the trial before giving up e.g.
CRUSH -f2 BACKUP will give up after only 2 failures.
CRUSH -f100 BACKUP will give up after 100 failures.
____________________________________
-t Only create CRUSH archive if 5% improvement
This creates a CRUSH archive only if it can improve the archive size
by 5%, otherwise it creates a conventional archive. It invokes the -c
option, which adds to the run time, as it needs to run the archiver
without CRUSH for comparison.
____________________________________
-t Only create CRUSH archive if "n"% improvement
As "-t", but allowing the user to set the threshold e.g.
CRUSH -t10 BACKUP CRUSH only if 10% better
____________________________________
-r Recurse subdirectories
This will search subdirectories from the specified directories, also
storing paths in the archive. Unlike PKZIP, CRUSH defaults to storing
pathnames with the files. However this is done in a very efficient
manner and so does not significantly increase the archive size (PKZIP
uses a space-consuming format for this e.g. searching a subdirectory
DOCUMENT\MYDOCS with 100 files would require an extra 1660 bytes,
whereas CRUSH would require just 16). Example:
CRUSH -r BACKUP \WP\DOCS\*.WP *.TXT
This will search \WP\DOCS and all its subdirectories for the filespec
*.WP, and the current directory and its subdirectories for *.TXT.
CRUSH will store the full path e.g. \WP\DOCS\HOME\DOC.WP etc.
See also the CRUSH option "-n" and UNCRUSH options "-i" and "-I" for
ignoring paths and drives.
__________________________________________________________________________
CRUSH Options Page 5
____________________________________
-: Set range(s) of dates
DATE OPTIONS. These are used to specify a date range for file
matching. If a single date is specified then this will be the
earliest date to be included. If a second date is specified, then
this is taken as the as the end date. Dates can be mixed in
"absolute" and "relative" format. The full syntax is:
[!]:[=]
Where: ! inverts the meaning of the range set. e.g. "range
1st-2nd" becomes "outside 1st-2nd"
= sets both the start and end date to the date following.
and can be:
Example:
DD/MM/YY absolute UK date 21/2/94
MM/DD/YY absolute US date (CRUSH determines which) 2/21/94
YY/MM/DD absolute JAPAN date ( " ) 94/2/21
DDMonYY absolute date in alternative format 21feb94
DDMon absolute date (current year) 21feb
-DD number of days before current date, OR -3
m-MM number of months OR m-2
y-YY number of years (truncates to 83 years) y-1
.name where date is taken from file/dir "name" .LASTBAC
The four date formats can be mixed, e.g. -:y-2:-5 (or /:y-2:-5)
specifies files created/modified between 2 years and 5 days ago.
-:y-99:5jan will select all files created on or before 5th Jan
(current year). -!:=-1 selects all files except yesterday's. The
".name" option allows compression of files relative to the date and
time of an existing file. The latter feature allows the user to issue
commands such as "compress all files modified/created since last
backup", using commands such as:
CRUSH -:.BACKTAG BACKUP
REM>BACKTAG
The REM>BACKTAG will create an empty file with the current date and
time, so that the next backup will start with the date and time of
that file.
General Examples: (all use the archive name "BACK")
CRUSH -:11feb BACK Compressing files modified/created on or
after February 11th of this year.
CRUSH -:-3 BACK Files modified/created today or during the 3
previous days.
CRUSH -:-0 BACK As above, but today only.
CRUSH -!:y-3 BACK Not files created during the last 3 years.
CRUSH -:m-4:m-3 BACK Will compress files modified/created between
4 and 3 months ago.
__________________________________________________________________________
CRUSH Options Page 6
____________________________________
-x Exclude pathspecs
In programs such as PKZIP and ARJ, the exclusion pathspecs can appear
in any position in the command-line. With CRUSH they MUST appear
AFTER the archive name with the other pathspecs. CRUSH limits the
user to 300 exclusion filespecs.
Examples: (pathspecs are all case-insensitive)
CRUSH BACKUP *.EXE -xTEST*.* *.COM
This will compress all files matching *.EXE and *.COM, but not those
matching TEST*.*. The order of these filespecs is irrelevant.
CRUSH -r BACKUP -xDOC\*.BAK -x*.TMP
This will recurse, searching for files to compress, but excluding
files that match the path and name DOC\*.BAK, or the name *.TMP in
any subdirectory.
CRUSH -r BACKUP [email protected] [email protected]
This will recurse, searching for file to compress, but excluding any
pathspecs in the response files NOTTHIS or ORTHIS.
____________________________________
-y Answer YES to all questions
This will allow CRUSH to compress without pausing for queries, such
as permission to overwrite an existing file.
____________________________________
-z Add CRUSH archive comment
This will prompt the user for an archive comment to add to the CRUSH
file. Ths will be displayed by UNCRUSH when uncrushing or verifying
an archive.
The user can automatically provide a CRUSH comment without the
program pausing for input by using the DOS echo command. e.g.
ECHO My Comment|CRUSH -z BACKUP
which will give the archive the comment "My Comment".
____________________________________
-v Show files for adding without CRUSHing
This will show which files CRUSH would compress without actually
compressing, with a summary at the end. If the output is re-directed
to a file, then the re-directed file will hold a simple list of files
(equivalent to PKZIP option "[email protected]") e.g.
CRUSH -v BACK > LIST Creating a list of matching files
that would be archived.
The archive name specified will be ignored.
__________________________________________________________________________
CRUSH Options Page 7
____________________________________
-n Store files without paths
This allows the user to prevent pathnames from being stored e.g.
CRUSH -n BACKUP MYDOC\*.DOC
would store files matching *.DOC, but without the path MYDOC\.
____________________________________
-Q Query each file to be archived
This allows the user to choose on-line which files are to be included
in the archive e.g.
CRUSH -Qr DOC *.WP
will search recursively (-r) for all files matching *.WP and query
whether each is to be added to the archive. The user has the option
to accept or reject all the remaining files at any point, or to abort
the compression. This option provides an easy way to construct a
response file, e.g. the following expanded example:
CRUSH -Qr DOC *.WP *.TXT > SAVE
would allow the user to select files for compression while also
creating a response file SAVE for future use, e.g. CRUSH DOC @SAVE.
____________________________________
-q QUIET mode, no output
This will run CRUSH without any display output, unless CRUSH needs to
prompt the user with a question (inhibited by -y). This is useful for
instances where CRUSH is called within BAT scripts or from within
another program.
____________________________________
-a Create an additional index
The price paid for creating CRUSH archives is that, although programs
such as PocketD Plus can still browse the contents of the archives,
searching for files inside CRUSH archives would be prohibitively slow
if each CRUSH archive had to be temporarily decompressed whilst
scanning. The -a option will force CRUSH to create an additional
external index with the extension ".CRI". PocketD Plus will use this
for searching (and also browsing) to allow files to be searched or
selected very quickly. This will obviously have an associated disk
space overhead, but this would not be significant on disks with small
cluster sizes (e.g. floppies), or where the CRUSH saving is already
substantial (i.e. more than 10%)
____________________________________
-e Use the existing archive for comparison
This will allow the user to test the compression improvement without
re-creating the original archive for comparison. CRUSH will still
need the files for compression to be available in uncompressed form.
The option -c must also be used. Make sure that the archive to be
compared is not already a CRUSH archive!
__________________________________________________________________________
CRUSH Options Page 8
____________________________________
-C Colour off
This will use whatever colour is currently in use rather than forcing
white on blue. This normally means white on black.
____________________________________
-C Set colour
This will allow the user to override the colour of the bar graph
displayed during compression. "n" is the normal colour attribute in
the range 0 to 7.
____________________________________
-s Minimise temporary disk space (slow!)
CRUSH will normally use about 25% extra temporary disk space when
running with the -f optimise option. If you do not have sufficient
space to run CRUSH with this option, then "-s" will reduce the space
CRUSH uses, but at the cost of a longer compression time. This option
is not recommended for routine use unless you are normally always
short of disk space. CRUSH does not make use of extended or expanded
memory.
____________________________________
-i Control information type
By default, CRUSH will display a bar graph.
If -i1 is specified, a more comprehensive table will be shown
instead, giving more information.
If -i2 is specified, CRUSH will still show a bar graph, but when -c
is selected it will simultaneously plot the file size, archive size
and CRUSH size, rather than just archive and CRUSH. This will allow
all three sizes to be compared, but will give limited resolution of
the difference between just the archive and CRUSH.
Note: CRUSH plots to a resolution of 1 in 114 (using the special half
width character "221")
____________________________________
-2 Set display of times to 24 hour clock
This will force the display of 24 hour clock times instead of 12 hour
during browsing.
__________________________________________________________________________
The UNCRUSH Program Page 9
The UNCRUSH program is used for uncompressing or viewing CRUSH archives.
It requires access to the corresponding uncompressing programs used by the
base archiver e.g. PKUNZIP for PKZIP files and ARJ for ARJ files. Unlike
CRUSH, UNCRUSH is copyrighted FREEWARE. You may use and distribute freely
providing that its intended use is not mis-represented and it is not
modified in any way.
USAGE: UNCRUSH [opts] archive [destination] [pathspecs] [>outfile]
Where:
[opts] These are options that control UNCRUSH's behaviour. e.g. -v
causes CRUSH to display the names of the compressed files
without uncompressing them. These can be grouped together
for brevity or specified one-by-one, e.g.
-ioq is equivalent to: -i -o -q
The user can choose to use "/" in place of "-" for
preference e.g. -i and /i are equivalent.
archive This is the name of the archive to be uncompressed e.g.
BACKUP or BACKUP.001 etc. If no extension is specified,
then UNCRUSH will look for known extensions that use the
specified name in the order CRU, CRI, ZIP, ARJ, LZH, ZOO,
HA then UC2. UNCRUSH cannot uncompress files with
non-standard extensions. Such files will need to be
re-named before using UNCRUSH, or uncompressed first using
PKUNZIP etc.
[destination] This is the destination path where files are to be
uncompressed. This must be terminated by ":" or "\" to
allow it to be distinguished from normal pathspecs (same
operation as PKUNZIP). Paths within the archive will be
combined with any specified destination path, e.g.
CRUSH BACKUP \WP\*.DOC followed by:
UNCRUSH BACKUP MYDOC\HOME\
will uncompress to MYDOC\HOME\WP\*.DOC
[pathspecs] These are the files to be uncompressed (defaulting to all
files). These can include paths e.g.
UNCRUSH SAVE \WP\*.DOC *.TXT
This will uncompress pathspecs from SAVE matching \WP\*.DOC
and any pathspecs with the filespec *.TXT. i.e. *.TXT will
match *.TXT and \WP\*.TXT, but \WP\*.DOC would not match
*.DOC. UNCRUSH can be set to optionally ignore stored
pathnames. As with CRUSH, UNCRUSH uses proper rather than
DOS wildcards (See CRUSH for details).
[>outfile] UNCRUSH will allow the user to create response or summary
files using re-directed output. See -v, -V and -l.
__________________________________________________________________________
UNCRUSH Options: Page 10
____________________________________
-v Display without uncompressing
This will cause UNCRUSH to report the pathspecs inside the archive
without uncompressing. This gives a sorted output reporting size,
date and time of the file stored. Attributes are not displayed, even
though stored.
____________________________________
-V Display archive comment only
This will simply display the archive comment and the name of the
archive. This is useful for cataloging purposes, allowing this
information to be appended to a reference file e.g.
UNCRUSH -V FRED >> REFFILE
____________________________________
-o Overwrite files without query
This will force UNCRUSH to overwrite files regardless of whether the
file already exists. UNCRUSH would normally inform the user if files
already exist with an option to skip or overwrite the file. UNCRUSH
helpfully also informs the user whether the file to be overwritten is
NEWER, OLDER, IDENTICAL or SAME DATE, DIFFERENT SIZE.
____________________________________
-u Uncompress NEWER or NEW files
This will only uncompress NEW or NEWER files from within the archive.
This will still prompt for overwrites, unless -o is also specified.
____________________________________
-a Uncompress NEW files
This will only uncompress NEW files.
____________________________________
-i Ignore paths in CRUSH file
This will ignore all paths inside the archive, therefore possibly
generating an overwrite warning if WP\FRED.DOC and \DOC2\FRED.DOC
exist in the same CRUSH file.
____________________________________
-I Only ignore drives in paths
As "-i", but only ignoring drive names stored in the CRUSH file. This
accommodates situations where a CRUSH command such as:
CRUSH BACKUP S:\WP\*.DOC
is run, storing a network drive letter with the path. A user on a
non-networked PC would then be unable to uncompress the CRUSH file
without losing the path. The -I option allows this to be overridden.
__________________________________________________________________________
UNCRUSH Options Page 11
____________________________________
-q Quiet mode: No output at all
This will inhibit all output from UNCRUSH, except where UNCRUSH
queries an overwrite.
____________________________________
-z Only suppress output of archiver
This will only suppress the output of the unarchiver run by UNCRUSH.
e.g. UNCRUSH may call PKUNZIP which normally displays information
while uncompressing. This option will inhibit this. This may not
always be safe if the unarchiver has an unusual problem, in which
case the error message the archiver displays will not be visible.
____________________________________
-e Extract even if not CRUSH archive
This is convenient if the user wants to use UNCRUSH to process any
archives, whether CRUSH or not. This will support any pathspecs
given, but will not support specified destination directories.
____________________________________
-l Only display a simple file list
This will replace the normal display by a simple list of files and
pathnames. This is most usefully used with -v to generate a response
file.
____________________________________
-2 Display times as 24-hour clock
This is only a cosmetic detail, but many users are firmly committed
to 12 or 24 hour clocks, in which case UNCRUSH will allow the default
12 hour clock file times to be replaced by a 24 hour clock times.
__________________________________________________________________________
Worked Examples Page 12
There are many routine archiving tasks that CRUSH could be used for. The
following selects a few that either take particular advantage of CRUSH
facilities, or that may be particularly relevant when first using CRUSH.
For simple examples see "Getting Started" at the beginning of this manual.
____________________________________
Generating a Response File for Future Backups
Most archivers allow the user to use a "response" file containing file and
path specifications to be used in addition to (or instead of) CRUSH
command-line parameters. This is convenient when a list is very large.
CRUSH allows the user to choose files for archiving on-line using the -Q
option. e.g.
CRUSH -rQv TEST *.C *.ASM >RESPLIST
This will search all subdirectories (-r), querying each file found (-Q),
but without actually creating an archive (-v). The output is directed to
the file RESPLIST. The user can then use this for future CRUSH archiving
in a command of the form:
CRUSH BACKUP @RESPLIST
____________________________________
Performing Archival Backups
CRUSH's option to backup files dated on or after a named file (not
supported by PKZIP etc.) makes it possible to create backups of all files
modified since the previous backup. This can be combined with CRUSH's
ability to automatically generate a unique filename, as follows:
BACK.BAT containing:
CRUSH -r:.LASTBAC [] *.DOC *.C *.H
IF ERRORLEVEL 1 ECHO Error occurred!
IF ERRORLEVEL 1 GOTO EXIT
REM>LASTBAC
:EXIT
The "[]" parameter replaces the normal archive name by a unique name
generated using the current date and time (e.g. 1CD29E33.ZIP, which uses
the hexadecimal value of the combined 32-bit date and time). CRUSH will
then search all subdirectories for all files matching *.DOC *.C or *.H
modified since the date and time of the file LASTBAC and add them to the
archive. If the archive step fails (e.g. out of memory etc.), the error is
reported and the command sequence ended. If successful, then "REM>LASTBAC"
will create an empty file with the current date and time for reference by
the next backup.
On the next occasion that the command "BACK" is run, CRUSH will only
search for files modified since the last backup.
__________________________________________________________________________
Worked Examples Page 13
____________________________________
Converting all Existing Archives to CRUSH
This would be a potentially mammoth task that would benefit from some
automation, unless you are willing to convert each file one-by-one. A good
choice for this task would be PocketD Plus v4.1 (D.EXE), as follows:
MD TMP
CD TMP
D .ZIP/W[PKUNZIP -d $w//CRUSH -ert $w//PAUSE//D /zd]Rq
This example converts ZIP files by running a command sequence of the
following type for each archive found:
PKUNZIP -d \C\BATS.ZIP Uncompress with subdirectories into TMP.
CRUSH -ert \C\BATS.ZIP (See below).
PAUSE Allow inspection of result.
D /zd Delete uncompressed files/dirs from TMP.
The CRUSH command compares the new CRUSH archive with the existing archive
(-e), but will not replace it unless the new archive is at least 5%
smaller (-t). The files originally compressed may also include paths, and
so CRUSH uses -r to search all uncompressed subdirectories created by the
"PKUNZIP -d" command. For those with a cautious disposition, the D.EXE
command-line includes the "q" option, allowing the user to confirm or
select each archive to be processed. The PAUSE command allows the user to
examine the output of CRUSH before the command "D /zd" deletes the files
and subdirectories temporarily uncompressed.
____________________________________
The UNDO and UNDO2 Programs
The registered version of CRUSH.EXE comes with two additional programs,
UNDO.EXE and UNDO2.EXE, which provide tiny alternatives to UNCRUSH.EXE for
unpacking an uncompressed CRUSH archive.
USAGE: UNDO crushname
UNDO2 crushname
UNDO.EXE is 3.8k and ignores any path information. UNDO2.EXE is 4.3k and
will also re-construct embedded paths. These programs can be included
within distribution archives that hold CRUSH archives, providing the
smallest package that will allow UNCRUSHing without additional programs.
Ideally UNDO.EXE and a CRU archive could be embedded inside an SFX
archive, e.g. using LHA:
CRUSH -l DEMO ! *.DOC
LHA A DEMO UNDO.EXE
LHA S DEMO
The "!" parameter above is the file "!" which contains a message displayed
when the archive DEMO.EXE is run. This can contain details of how to
uncompress the CRUSH archive, e.g. "Unpack the CRUSH archive by typing
UNDO DEMO.CRU after the DEMO.EXE executable has finished decompression."
The user may choose to rename UNDO2.EXE to UNDO.EXE or some other
convenient name. Note that distribution of CRUSH archives requires a
distribution licence (see REGISTER.DOC).
__________________________________________________________________________
Configuration Page 14
__________________________________
Configuration of CRUSH and UNCRUSH
CRUSH and UNCRUSH can be configured using environment variables, as
follows:
The CRUSH variable:
This is particularly important if you decide not to use the default
PKZIP used by CRUSH e.g.
SET CRUSH=-j
will force CRUSH to always use ARJ by default. Other options can also
be added e.g.
SET CRUSH=-jCc
will also force the normal display colour and always force a
comparison between ARJ and CRUSH when creating a CRUSH file.
The UNCRUSH variable:
This is less critical, but an example usage might be:
SET UNCRUSH=-2e
which would use the 24 hour clock and also allow UNCRUSH to be used
for uncompressing ordinary PKZIP, ARJ, LHA, ZOO, HA and UC archives.
Environment variables should be set in your AUTOEXEC.BAT, otherwise they
will be lost next time the system is re-booted.
__________________________________________________________________________
Technical Details Page 15
This information is only of interest to 3rd party developers who may want
to provide support for CRUSH archives.
__________________________________
Structure of CRUSH file (.CRU)
Address Length in Bytes Description
000000 14 CRUSH v1.3
00000E 2 Chksum
000010 2 Number of paths (only 0-255 supported)
000012 2 Number of files
000014 2 Reserved
000016 4 Totalsize of files + header length(26)
00001A "totalsize" Data
; directory held at offset "Totalsize of files + header length(26)"
000000 1 Path number
000001 1 Attribute
000002 2 Time
000004 2 Date
000006 4 Size
00000A 13 Name
000017 1 Reserved
(above repeated "Number of files" times)
; "n" Paths
path1 Each terminated by NULL
path2
..
; Archive comment
comment Terminated by NULL
__________________________________
Structure of CRUSH fast Index (.CRI)
As CRU but with Totalsize field set to 0 + Headerlen(26)
000016 4 Header length(26)
This is a Shareware copy of CRUSH v1.3
The documents MANUAL.DOC and README can be printed directly
to a conventional printer. Alternatively they can be read into
a Wordprocessor for printing using a Laser printer. If you
do this, then you should set the minimum margins that your
Wordprocessor allows, and select a 12 point Courier Font.
Fed up with limited compression performance
of Stacker, PKZIP (2.04g), ZOO, ARJ and LHA?
CRUSH will usually give 5%-50% improved
compression over any other DOS compression
tool, & yet allows the user to continue using
the archiver already in use. CRUSH is fast &
the ideal choice for users keen to save disk
space. Too good to be true? No! Try it!
PocketD v4.1 compatible - Registration $29+
__________________________________________________________________________
CRUSH v1.3 Readme File
__________________________________________________________________________
CRUSH is a new shareware product from the same author as the awarding
winning DOS file manager PocketD Plus ("BEST UTILITY 1992" PsL and joint
runner-up WHAT PC's "BEST UTILITY 1994" with Stacker v4.0 & Dr Solomon's
Virus Toolkit). PocketD Plus has been upgraded to v4.1 to support CRUSH.
>>>>>>>> WHAT IS CRUSH ?
CRUSH is a compression tool that can work with your existing archiver
to dramatically reduce the size of archives created. In many
instances CRUSH achieves an average 2:1 advantage over PKZIP and 8:1
over uncompressed files. However CRUSH is neither slow nor
inconvenient to use. The command-line syntax is essentially similar
to PKZIP, but with many powerful extensions.
CRUSH will work with any of PKZIP, ARJ, LHA, ZOO, UC2 and HA. The
archivers PKZIP, UC2 and ARJ are Shareware and require registration
payments. LHA, ZOO and HA are Copyrighted Freeware.
>>>>>>>> HOW DOES IT WORK ?
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will
generally compress better than small files, a property used by Unix
users who follow the maxim "always tar before compress" (joining
files together before compressing). CRUSH will automatically do this
for you, generating a single file with an extension "CRU" that it
compresses using your chosen archiver (default PKZIP). Extraction of
files is then very easy: UNCRUSH works in the same way as PKUNZIP.
CRUSH gets the most from this compression trick by taking it one step
further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to
recognise 7 different compressed header types), and orders them
accordingly. This yields a very good default fast compression.
Given more time CRUSH can do better by optionally performing a series
of trials to squeeze out extra compression. The algorithm for this
uses an intelligent re-ordering mechanism which analyses the results
of each intermediate test in order to determine which ordering to try
next. This was developed over a period of 2 years where it was
successfully used to reduce the file size of PocketD Plus to the
absolute minimum. This technique allows CRUSH to find near optimum
compression in a few minutes that might take hundreds of years using
more brute-force methods!
>>>>>>>> HOW GOOD IS IT?
Using CRUSH would not be worthwhile if it yielded a narrow advantage
over existing archivers, but in many situations it is capable of
delivering dramatically better compression. The results below are
genuine random tests performed on files taken from a 250-user PC
server and from a publically available CD-ROM.
All archivers were run with maximum compression, except CRUSH which
was set to minimum. The figures for Stacker and DoubleSpace are
commercially quoted performance figures for comparison, not test
results. All the figures quote the compression ratio in terms of disk
space used rather than actual file sizes (8k cluster assumed) to
allow comparison with Stacker 4.0. This does not significantly affect
the comparison between the other archivers (Figures for ZOO are not
quoted as it uses the same compression algorithm as LHA. Figures for
UC2 are not quoted as support for this has only just been added).
>>>>>>>> (1) CRUSH at its BEST -- Working with small data files
CRUSH works best with collections of similar small files. In a block test
of 128 directories (each compressed to its own archive) containing 2349
wordprocessing files (total 33 Megabytes), CRUSH with minimum optimisation
generated the following average compression ratio, calculated by:
Ratio = (disk space used by uncompressed files)/(space after compression)
Ratio
CRUSH+HA 7.95
CRUSH+PKZIP 7.82
CRUSH+ARJ 6.16
CRUSH+LHA 5.46
HA 0.98 4.32
PKZIP 2.04g 4.11
ARJ 2.3 4.18
LHA 2.11 4.12
Stacker 4.0 2.50
DoubleSpace 1.90
Orig Files 1.00
CRUSH clearly yields a substantial improvement in all cases. Its worst
result is with LHA, but this is still much better than any non-CRUSH
compression.
>>>>>>>> HOW FAST IS CRUSH ?
These results might be of limited value if the cost in time for
compression was great. The chart below shows the compression times for 6
wordprocessing files, totalling 150k on a 486SX25 with a ramdrive:
Seconds
CRUSH+HA 11.04
CRUSH+ZIP 3.51
CRUSH+ARJ 3.30
CRUSH+LHA 3.68
CRUSH+ZOO 8.57
HA 0.98 10.98
PKZIP 2.04 2.26
ARJ 2.3 3.02
LHA 2.11 3.30
ZOO 2.1 7.85
From these compression and speed results it can be seem that CRUSH with HA
0.98 offers the best overall compression, but that CRUSH with PKZIP or ARJ
does nearly as well, but are both over 3 times faster.
>>>>>>>> (2) CRUSH at its WORST -- Working with large or dissimilar files
CRUSH has the most difficulty when given large or dissimilar files. A good
example of this might be a Shareware release file which contains a mixture
of documents, executable and other files. A test with minimum optimisation
on 40 random archive files from the ASP-CD ROM (17 Megabytes) yielded the
following results:
Ratio
CRUSH+HA 2.84
CRUSH+ZIP 2.80
HA 0.98 2.76
PKZIP 2.04g 2.70
ARJ 2.3 2.70
LHA 2.11 2.66
Stacker 4.0 (2.50)
Doublespace (1.90)
Orig Files 1.00
Here, improved performance is somewhat less than the previous example,
corresponding to a 3.7% improvement with PKZIP. Many of the compressions
yielded a 0% improvement because although the newly compressed file may
have been smaller, it still occupied the same number of disk allocation
units (clusters). The average improvement in actual file size (important
for file downloads) was 5.6% for PKZIP, with a low of 1% and high of 28%.
The figures for Stacker and DoubleSpace are bracketed as they almost
certainly greatly overestimate their performances in these cases.
>>>>>>>> I USE STACKER. IS THERE MERIT IN USING CRUSH ?
On the fly compression provided by products such as Stacker offers
convenient but low performance compression. Stacker may make your 100 Mb
drive look like 250 Mb, but CRUSH may make it look like 800 Mb. On the fly
compression also has performance penalties and there is a question mark
over its safety.
Of course, CRUSH can safely be used in conjunction with Stacker to obtain
the highest possible net space saving.
>>>>>>>> IS IT WORTH MY WHILE USING CRUSH ?
If your PC is loaded with applications, but little data, then CRUSH may
not help that much. If your PC or PC server typically holds many source
files, database files or wordprocessing documents, then the advantages
might be enormous. A beta test site for CRUSH had vast numbers of
wordprocessing files for which CRUSH was able to achieve a compression
ratio of 16:1 where PKZIP had only yielded 6:1.
>>>>>>>> ARE THERE ANY DRAWBACKS IN USING CRUSH ?
CRUSH requires a significant quantity of temporary filespace whilst
compressing. In the default mode it will typically need 3.0 Mb of
temporary disk space available in order to compress 2.0 Mb of files. The
same is true when uncompressing. To extract a single 1k file from an
archive that contains 1 Mb will require 1 Mb of temporary file space.
CRUSH will not allow the user to update a single file or group of files
within a CRUSH archive. The entire archive must be re-created. It will
therefore be less useful to users who want to regularly update the same
archive to reflect frequent changes.
CRUSH is new and therefore many 3rd party programs will not yet be able to
search or view CRUSHed files. However these will appear, and the very
capable PocketD Plus v4.1 can already do this, allowing viewing of files
inside CRUSH archives with the same ease as any other archive type.
>>>>>>>> ARE THERE ANY OTHER ADVANTAGES IN USING CRUSH ?
CRUSH supports features such as recursive directory searching, storing of
paths, archive comments, file inclusion/exclusion by name and date, as
other archivers. However CRUSH also adds its own special facilities.
1. On-line Selection of Files
CRUSH allows the user to select files for archiving from an on-line
prompt, rather than forcing files to be always explicitly specified
in the command-line. This allows the user to issue commands such as
"Search the drive for files matching *.C modified during the last 6
days and present each matching name for acceptance or rejection".
2. Automatic Archive Name Generation
CRUSH has an option to automatically generate unique archive names
based on the current date and time. This is an ideal mechanism for
creating multiple generation backups.
3. Relative and Backup Date Testing
Unlike programs such as ARJ and PKZIP, CRUSH allows relative dates to
be specified, e.g. "CRUSH -r:-4 BACKUP" will search for and compress
files modified today or during the previous 4 days. CRUSH also allows
a "compress-since-last-backup" feature by allowing the comparison
with a named file date and time, e.g. "CRUSH -:.LASTBAC BACKUP" will
compress files modified since the date and time of the file LASTBAC.
4. Safer Decompression
UNCRUSH will helpfully tell you that a file to be de-compressed
already exists, and also if it is older, newer or identical.
5. CRUSH Supports Proper Wildcards
Unlike DOS (and PKZIP etc.), CRUSH supports proper wildcards. e.g.
the DOS wildcard *FRED.* would match a file called JOE! CRUSH
correctly implements "*" as any sequence of characters (including
none) and "?" as a single character.
6. User-specified Thresholds
CRUSH can be set to create a conventional archive where it cannot
improve by a specified percentage improved compression.
>>>>>>>> HOW DO I COMPARE CRUSH AND PKZIP (OR OTHER) PERFORMANCE ?
CRUSH has a convenient option "-c" which will run the chosen archiver
as well as performing a CRUSH archive operation. The results of this
are displayed as a bar graph (or table, if required).
>>>>>>>> HOW MUCH EXTRA WILL MAXIMUM CRUSH COMPRESSION GIVE ?
The cost in time for turning on extra optimisation in CRUSH is large.
Adding the -f option will probably increase compression time by a
factor of 5-10 times the default minimum, probably yielding between
1%-10% extra compression. However if you want to compress to the
minimum, then you may be happy to leave it overnight with -f200!
_________________________________
CRUSH v1.3
**** Shareware Manual ****
__________________________________
File Compression Tool
CRUSH (TM) Copyright Jeff Rollason, PocketWare (TM) 1994
All Rights Reserved
All Trademarks Are Acknowledged
No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated
into any other language in whole or in part, in any form or
by any means, whether it be electronic, mechanical,
magnetic, optical, manual or otherwise, without prior
written consent of PocketWare.
PocketWare PO Box 2369, Hendon, London NW4 1NR, England.
CIS 100031,3537. Internet [email protected]
__________________________________________________________________________
Contents:
CONTENTS: Page
Getting Started: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The CRUSH program: . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Default use of PKZIP . . . . . . . . . . . . . . . . . . . . . . . 3
-j Use ARJ . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-o Use ZOO . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-l Use LHA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-h Use HA . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-u Use UC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
-m Moves file to archive . . . . . . . . . . . . . . . . . . . . 3
-c Compare with and without CRUSH . . . . . . . . . . . . . . . 3
-f Optimise until 5 failed attempts to improve compression . . . 4
-f
-t Only create CRUSH archive if 5% improvement . . . . . . . . . 4
-t
-r Recurse subdirectories . . . . . . . . . . . . . . . . . . . 4
-: Set range(s) of dates . . . . . . . . . . . . . . . . . . . . 5
-x Exclude pathspecs . . . . . . . . . . . . . . . . . . . . . . 6
-y Answer YES to all questions . . . . . . . . . . . . . . . . . 6
-z Add CRUSH archive comment . . . . . . . . . . . . . . . . . . 6
-v Show files for adding without CRUSHing . . . . . . . . . . . 6
-n Store files without paths . . . . . . . . . . . . . . . . . . 7
-Q Query each file to be archived. . . . . . . . . . . . . . . . 7
-q QUIET mode, no output . . . . . . . . . . . . . . . . . . . . 7
-a Create an additional index . . . . . . . . . . . . . . . . . 7
-e Use the existing archive for comparison . . . . . . . . . . . 7
-C Colour off . . . . . . . . . . . . . . . . . . . . . . . . . 8
-C
-s Minimise temporary disk space (slow!) . . . . . . . . . . . . 8
-i
-2 Set display of times to 24 hour clock . . . . . . . . . . . . 8
The UNCRUSH Program: . . . . . . . . . . . . . . . . . . . . . . . . . . 9
-v Display without uncompressing . . . . . . . . . . . . . . . .10
-V Display archive comment only . . . . . . . . . . . . . . . .10
-o Overwrite files without query . . . . . . . . . . . . . . . .10
-u Uncompress NEWER or NEW files . . . . . . . . . . . . . . . .10
-a Uncompress NEW files . . . . . . . . . . . . . . . . . . . .10
-i Ignore paths in CRUSH file . . . . . . . . . . . . . . . . .10
-I Only ignore drives in paths . . . . . . . . . . . . . . . . .10
-q Quiet mode: No output at all . . . . . . . . . . . . . . . .11
-z Only suppress output of archiver . . . . . . . . . . . . . .11
-e Extract even if not CRUSH archive . . . . . . . . . . . . . .11
-l Only display a simple file list . . . . . . . . . . . . . . .11
-2 Display times as 24-hour clock . . . . . . . . . . . . . . .11
Worked Examples: . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
The UNDO and UNDO2 Programs: . . . . . . . . . . . . . . . . . . . . . .13
Configuration: . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Technical Details: . . . . . . . . . . . . . . . . . . . . . . . . . . .15
_________________________________________________________________________
Getting Started Page 1
____________________________________
Installation
CRUSH installation is very simple. The user need only copy the contents of
the release disk to the desired directory. A file INSTALL.BAT is provided
to do this for you. Your chosen directory should be within your search
path (See the PATH variable in your DOS documentation).
In order to be able to use CRUSH, you must have one of the archivers
PKZIP, ARJ, LHA, ZOO, HA and UC.
____________________________________
What is CRUSH?
CRUSH is a command-line tool that uses your existing archiver PKZIP, ARJ,
LHA, ZOO, HA or UC to generate smaller archives than it could alone. With
many applications this improvement may be less than 5%, but dramatic
improvements of 10%-70% are much more typical. A block test of 128
archives totalling 2349 wordprocessing files (see README) averaged a 47%
improvement (100k ZIP reduced to 53k CRUSH!). CRUSH is ideally suited to
users who regularly archive material or who just need to save disk space.
There is no other compression tool for DOS (as of June 1994) that can
match the compression performance of CRUSH, and most do not come close.
____________________________________
CRUSH and other Archivers
CRUSH is used from the command-line in much the same way as archivers such
as PKZIP and ARJ. If you are already familiar with these, then you should
be able to adapt to CRUSH with very little difficulty. If you are a ZOO,
LHA or HA user, then you will observe some changes, but will find the
basic operation of CRUSH very similar.
____________________________________
Simple use of CRUSH
To create a CRUSH archive called BACKUP containing all the files in the
current directory requires the following simple command:
CRUSH BACKUP
This will create the file BACKUP.ZIP (PKZIP must be available). The user
can be more selective by adding filespecs, as follows:
CRUSH BACKUP *.DOC README MAN*.*
This will only save files with the specified filespecs. The user may also
want to receive some feedback about how much space is being saved. The
"-c" (compare) option will allow a comparison to be made:
CRUSH -c BACKUP *.DOC README MAN*.*
Once created, a CRUSH archive can be uncompressed using UNCRUSH in much
the same way as PKUNZIP is used. e.g. UNCRUSH BACKUP *.DOC. This only
extracts files matching *.DOC. The user is advised to read the "Worked
Examples" section for more details of CRUSH usage, and also the README
file. Simply type "CRUSH" to obtain on-line help.
_________________________________________________________________________
The CRUSH program Page 2
This is the program that will replace the use of PKZIP, LHA, ARJ, ZOO, HA
and UC. Whichever of these you already use will still be needed, but CRUSH
will run it for you. The command-line syntax of CRUSH is, for most cases,
identical to PKZIP usage. CRUSH preserves dates, times and attributes.
USAGE: CRUSH [opts] archive [pathspecs] [@lists] [>outfile]
Where:
[opts] These are options that control CRUSH's behaviour. e.g. -r
causes CRUSH to search subdirectories. These can be grouped
together for brevity or specified one-by-one, e.g.
-rca is equivalent to: -r -c -a
The user can choose to use "/" in place of "-" for
preference. e.g. -r and /r are equivalent.
archive This is the name of the archive to be created e.g. BACKUP
or BACKUP.001 etc. If no extension is specified, then the
default extension for the archiver used will be adopted
(default PKZIP). If the special name "[]" is given (e.g.
CRUSH []), then CRUSH will generate a unique archive name
based on the current date and time (assuming that archives
are not created within 2 seconds of each other).
[pathspecs] These are the files to be compressed (defaulting to all
files in the current directory). e.g.
CRUSH SAVE \WP\*.DOC *.TXT
This will compress into SAVE.ZIP all files matching *.DOC
from the directory \WP and all files matching *.TXT from
the current directory. The path \WP\ will also be stored in
the archive, to be re-created by UNCRUSH. UNCRUSH can
optionally ignore stored pathnames.
CRUSH uses proper rather than DOS wildcards. e.g. the DOS
wildcard *FRED.* will match a file called JOE because
*FRED.* and *.* are treated by DOS as equivalent. CRUSH
interprets "*" as any sequence of characters, including
zero length. See also the "-x" EXCLUSION filespecs.
[@lists] CRUSH will accept response files containing lists of files
to be processed. These should contain one pathspec per line
and can contain comments starting with ";" e.g.
*.EXE
\WP\*.DOC ; save my docs
; Fred's stuff here onwards
\BIN\*.EXE
Unlike PKZIP, the response file can be of any length (PKZIP
limits the user to 500 filespecs).
[>outfile] CRUSH can generate a response file by re-directing the
output to a file for later use e.g. CRUSH DOCS >SAVE
__________________________________________________________________________
CRUSH Options Page 3
CRUSH will default to using PKZIP unless -j, -o, -l, -h or -u is
specified. PKZIP is the world's best known archiver, written by Paul Katz
and marketed as Shareware by PKWARE. CRUSH will work with any version of
PKZIP, but the user is recommended to use PKZIP v2.04 or later, which
achieves significantly better compression than v1.x.
____________________________________
-j Use ARJ
This instructs CRUSH to use Robert K Jung's "ARJ" program instead of
PKZIP. This can be specified as a general default using the CRUSH
environment variable e.g. SET CRUSH=-j
Example:
CRUSH BACKUP Use PKZIP
CRUSH -j BACKUP Use ARJ
____________________________________
-o Use ZOO
This will use the ZOO program, creating ZOO files.
____________________________________
-l Use LHA
This will use Haruyasu Yoshizaki's "LHA" program, creating LZH files.
____________________________________
-h Use HA
This will use Harri Hirvola's "HA" program, creating HA files. HA
produces very small archives, but is quite slow.
____________________________________
-u Use UC2
This uses Ad Infinitum Programs's "UC" program. This uses a great of
DOS memory and will probably require the added program US.EXE to
allow CRUSH access to the 80k it needs. e.g. US CRUSH -u SAVE
____________________________________
-m Moves file to archive
This will delete the original files after they have been successfully
compressed.
____________________________________
-c Compare with and without CRUSH
This allows CRUSH to show how much filespace has been saved over the
archiver alone. This will make CRUSH slower as an additional
compression is needed in order to make a comparison (unless -e is
also used). The results are displayed as a bar graph, plotting
archive and CRUSH sizes. The original file size can also be plotted
by adding the option -i2.
__________________________________________________________________________
CRUSH Options Page 4
____________________________________
-f Optimise until 5 failed attempts to improve compression
This will make CRUSH experiment with different orderings to improve
the compression. CRUSH will end when it has failed 5 times to find an
improvement. This will increase the run time of CRUSH by at least 5
times. Each time it provides an improvement, the time taken
increases. CRUSH is unlikely to take more than 15 times the normal
compress time.
The results of this trial are displayed as two bar graphs, showing
the size of the first and best CRUSH compression. (See option "-s").
____________________________________
-f
As "-f", but allowing the user to specify how long CRUSH is to
continue the trial before giving up e.g.
CRUSH -f2 BACKUP will give up after only 2 failures.
CRUSH -f100 BACKUP will give up after 100 failures.
____________________________________
-t Only create CRUSH archive if 5% improvement
This creates a CRUSH archive only if it can improve the archive size
by 5%, otherwise it creates a conventional archive. It invokes the -c
option, which adds to the run time, as it needs to run the archiver
without CRUSH for comparison.
____________________________________
-t
As "-t", but allowing the user to set the threshold e.g.
CRUSH -t10 BACKUP CRUSH only if 10% better
____________________________________
-r Recurse subdirectories
This will search subdirectories from the specified directories, also
storing paths in the archive. Unlike PKZIP, CRUSH defaults to storing
pathnames with the files. However this is done in a very efficient
manner and so does not significantly increase the archive size (PKZIP
uses a space-consuming format for this e.g. searching a subdirectory
DOCUMENT\MYDOCS with 100 files would require an extra 1660 bytes,
whereas CRUSH would require just 16). Example:
CRUSH -r BACKUP \WP\DOCS\*.WP *.TXT
This will search \WP\DOCS and all its subdirectories for the filespec
*.WP, and the current directory and its subdirectories for *.TXT.
CRUSH will store the full path e.g. \WP\DOCS\HOME\DOC.WP etc.
See also the CRUSH option "-n" and UNCRUSH options "-i" and "-I" for
ignoring paths and drives.
__________________________________________________________________________
CRUSH Options Page 5
____________________________________
-: Set range(s) of dates
DATE OPTIONS. These are used to specify a date range for file
matching. If a single date is specified then this will be the
earliest date to be included. If a second date is specified, then
this is taken as the as the end date. Dates can be mixed in
"absolute" and "relative" format. The full syntax is:
[!]:[=]
Where: ! inverts the meaning of the range set. e.g. "range
1st-2nd" becomes "outside 1st-2nd"
= sets both the start and end date to the date following.
and
Example:
DD/MM/YY absolute UK date 21/2/94
MM/DD/YY absolute US date (CRUSH determines which) 2/21/94
YY/MM/DD absolute JAPAN date ( " ) 94/2/21
DDMonYY absolute date in alternative format 21feb94
DDMon absolute date (current year) 21feb
-DD number of days before current date, OR -3
m-MM number of months OR m-2
y-YY number of years (truncates to 83 years) y-1
.name where date is taken from file/dir "name" .LASTBAC
The four date formats can be mixed, e.g. -:y-2:-5 (or /:y-2:-5)
specifies files created/modified between 2 years and 5 days ago.
-:y-99:5jan will select all files created on or before 5th Jan
(current year). -!:=-1 selects all files except yesterday's. The
".name" option allows compression of files relative to the date and
time of an existing file. The latter feature allows the user to issue
commands such as "compress all files modified/created since last
backup", using commands such as:
CRUSH -:.BACKTAG BACKUP
REM>BACKTAG
The REM>BACKTAG will create an empty file with the current date and
time, so that the next backup will start with the date and time of
that file.
General Examples: (all use the archive name "BACK")
CRUSH -:11feb BACK Compressing files modified/created on or
after February 11th of this year.
CRUSH -:-3 BACK Files modified/created today or during the 3
previous days.
CRUSH -:-0 BACK As above, but today only.
CRUSH -!:y-3 BACK Not files created during the last 3 years.
CRUSH -:m-4:m-3 BACK Will compress files modified/created between
4 and 3 months ago.
__________________________________________________________________________
CRUSH Options Page 6
____________________________________
-x Exclude pathspecs
In programs such as PKZIP and ARJ, the exclusion pathspecs can appear
in any position in the command-line. With CRUSH they MUST appear
AFTER the archive name with the other pathspecs. CRUSH limits the
user to 300 exclusion filespecs.
Examples: (pathspecs are all case-insensitive)
CRUSH BACKUP *.EXE -xTEST*.* *.COM
This will compress all files matching *.EXE and *.COM, but not those
matching TEST*.*. The order of these filespecs is irrelevant.
CRUSH -r BACKUP -xDOC\*.BAK -x*.TMP
This will recurse, searching for files to compress, but excluding
files that match the path and name DOC\*.BAK, or the name *.TMP in
any subdirectory.
CRUSH -r BACKUP [email protected] [email protected]
This will recurse, searching for file to compress, but excluding any
pathspecs in the response files NOTTHIS or ORTHIS.
____________________________________
-y Answer YES to all questions
This will allow CRUSH to compress without pausing for queries, such
as permission to overwrite an existing file.
____________________________________
-z Add CRUSH archive comment
This will prompt the user for an archive comment to add to the CRUSH
file. Ths will be displayed by UNCRUSH when uncrushing or verifying
an archive.
The user can automatically provide a CRUSH comment without the
program pausing for input by using the DOS echo command. e.g.
ECHO My Comment|CRUSH -z BACKUP
which will give the archive the comment "My Comment".
____________________________________
-v Show files for adding without CRUSHing
This will show which files CRUSH would compress without actually
compressing, with a summary at the end. If the output is re-directed
to a file, then the re-directed file will hold a simple list of files
(equivalent to PKZIP option "[email protected]") e.g.
CRUSH -v BACK > LIST Creating a list of matching files
that would be archived.
The archive name specified will be ignored.
__________________________________________________________________________
CRUSH Options Page 7
____________________________________
-n Store files without paths
This allows the user to prevent pathnames from being stored e.g.
CRUSH -n BACKUP MYDOC\*.DOC
would store files matching *.DOC, but without the path MYDOC\.
____________________________________
-Q Query each file to be archived
This allows the user to choose on-line which files are to be included
in the archive e.g.
CRUSH -Qr DOC *.WP
will search recursively (-r) for all files matching *.WP and query
whether each is to be added to the archive. The user has the option
to accept or reject all the remaining files at any point, or to abort
the compression. This option provides an easy way to construct a
response file, e.g. the following expanded example:
CRUSH -Qr DOC *.WP *.TXT > SAVE
would allow the user to select files for compression while also
creating a response file SAVE for future use, e.g. CRUSH DOC @SAVE.
____________________________________
-q QUIET mode, no output
This will run CRUSH without any display output, unless CRUSH needs to
prompt the user with a question (inhibited by -y). This is useful for
instances where CRUSH is called within BAT scripts or from within
another program.
____________________________________
-a Create an additional index
The price paid for creating CRUSH archives is that, although programs
such as PocketD Plus can still browse the contents of the archives,
searching for files inside CRUSH archives would be prohibitively slow
if each CRUSH archive had to be temporarily decompressed whilst
scanning. The -a option will force CRUSH to create an additional
external index with the extension ".CRI". PocketD Plus will use this
for searching (and also browsing) to allow files to be searched or
selected very quickly. This will obviously have an associated disk
space overhead, but this would not be significant on disks with small
cluster sizes (e.g. floppies), or where the CRUSH saving is already
substantial (i.e. more than 10%)
____________________________________
-e Use the existing archive for comparison
This will allow the user to test the compression improvement without
re-creating the original archive for comparison. CRUSH will still
need the files for compression to be available in uncompressed form.
The option -c must also be used. Make sure that the archive to be
compared is not already a CRUSH archive!
__________________________________________________________________________
CRUSH Options Page 8
____________________________________
-C Colour off
This will use whatever colour is currently in use rather than forcing
white on blue. This normally means white on black.
____________________________________
-C
This will allow the user to override the colour of the bar graph
displayed during compression. "n" is the normal colour attribute in
the range 0 to 7.
____________________________________
-s Minimise temporary disk space (slow!)
CRUSH will normally use about 25% extra temporary disk space when
running with the -f optimise option. If you do not have sufficient
space to run CRUSH with this option, then "-s" will reduce the space
CRUSH uses, but at the cost of a longer compression time. This option
is not recommended for routine use unless you are normally always
short of disk space. CRUSH does not make use of extended or expanded
memory.
____________________________________
-i
By default, CRUSH will display a bar graph.
If -i1 is specified, a more comprehensive table will be shown
instead, giving more information.
If -i2 is specified, CRUSH will still show a bar graph, but when -c
is selected it will simultaneously plot the file size, archive size
and CRUSH size, rather than just archive and CRUSH. This will allow
all three sizes to be compared, but will give limited resolution of
the difference between just the archive and CRUSH.
Note: CRUSH plots to a resolution of 1 in 114 (using the special half
width character "221")
____________________________________
-2 Set display of times to 24 hour clock
This will force the display of 24 hour clock times instead of 12 hour
during browsing.
__________________________________________________________________________
The UNCRUSH Program Page 9
The UNCRUSH program is used for uncompressing or viewing CRUSH archives.
It requires access to the corresponding uncompressing programs used by the
base archiver e.g. PKUNZIP for PKZIP files and ARJ for ARJ files. Unlike
CRUSH, UNCRUSH is copyrighted FREEWARE. You may use and distribute freely
providing that its intended use is not mis-represented and it is not
modified in any way.
USAGE: UNCRUSH [opts] archive [destination] [pathspecs] [>outfile]
Where:
[opts] These are options that control UNCRUSH's behaviour. e.g. -v
causes CRUSH to display the names of the compressed files
without uncompressing them. These can be grouped together
for brevity or specified one-by-one, e.g.
-ioq is equivalent to: -i -o -q
The user can choose to use "/" in place of "-" for
preference e.g. -i and /i are equivalent.
archive This is the name of the archive to be uncompressed e.g.
BACKUP or BACKUP.001 etc. If no extension is specified,
then UNCRUSH will look for known extensions that use the
specified name in the order CRU, CRI, ZIP, ARJ, LZH, ZOO,
HA then UC2. UNCRUSH cannot uncompress files with
non-standard extensions. Such files will need to be
re-named before using UNCRUSH, or uncompressed first using
PKUNZIP etc.
[destination] This is the destination path where files are to be
uncompressed. This must be terminated by ":" or "\" to
allow it to be distinguished from normal pathspecs (same
operation as PKUNZIP). Paths within the archive will be
combined with any specified destination path, e.g.
CRUSH BACKUP \WP\*.DOC followed by:
UNCRUSH BACKUP MYDOC\HOME\
will uncompress to MYDOC\HOME\WP\*.DOC
[pathspecs] These are the files to be uncompressed (defaulting to all
files). These can include paths e.g.
UNCRUSH SAVE \WP\*.DOC *.TXT
This will uncompress pathspecs from SAVE matching \WP\*.DOC
and any pathspecs with the filespec *.TXT. i.e. *.TXT will
match *.TXT and \WP\*.TXT, but \WP\*.DOC would not match
*.DOC. UNCRUSH can be set to optionally ignore stored
pathnames. As with CRUSH, UNCRUSH uses proper rather than
DOS wildcards (See CRUSH for details).
[>outfile] UNCRUSH will allow the user to create response or summary
files using re-directed output. See -v, -V and -l.
__________________________________________________________________________
UNCRUSH Options: Page 10
____________________________________
-v Display without uncompressing
This will cause UNCRUSH to report the pathspecs inside the archive
without uncompressing. This gives a sorted output reporting size,
date and time of the file stored. Attributes are not displayed, even
though stored.
____________________________________
-V Display archive comment only
This will simply display the archive comment and the name of the
archive. This is useful for cataloging purposes, allowing this
information to be appended to a reference file e.g.
UNCRUSH -V FRED >> REFFILE
____________________________________
-o Overwrite files without query
This will force UNCRUSH to overwrite files regardless of whether the
file already exists. UNCRUSH would normally inform the user if files
already exist with an option to skip or overwrite the file. UNCRUSH
helpfully also informs the user whether the file to be overwritten is
NEWER, OLDER, IDENTICAL or SAME DATE, DIFFERENT SIZE.
____________________________________
-u Uncompress NEWER or NEW files
This will only uncompress NEW or NEWER files from within the archive.
This will still prompt for overwrites, unless -o is also specified.
____________________________________
-a Uncompress NEW files
This will only uncompress NEW files.
____________________________________
-i Ignore paths in CRUSH file
This will ignore all paths inside the archive, therefore possibly
generating an overwrite warning if WP\FRED.DOC and \DOC2\FRED.DOC
exist in the same CRUSH file.
____________________________________
-I Only ignore drives in paths
As "-i", but only ignoring drive names stored in the CRUSH file. This
accommodates situations where a CRUSH command such as:
CRUSH BACKUP S:\WP\*.DOC
is run, storing a network drive letter with the path. A user on a
non-networked PC would then be unable to uncompress the CRUSH file
without losing the path. The -I option allows this to be overridden.
__________________________________________________________________________
UNCRUSH Options Page 11
____________________________________
-q Quiet mode: No output at all
This will inhibit all output from UNCRUSH, except where UNCRUSH
queries an overwrite.
____________________________________
-z Only suppress output of archiver
This will only suppress the output of the unarchiver run by UNCRUSH.
e.g. UNCRUSH may call PKUNZIP which normally displays information
while uncompressing. This option will inhibit this. This may not
always be safe if the unarchiver has an unusual problem, in which
case the error message the archiver displays will not be visible.
____________________________________
-e Extract even if not CRUSH archive
This is convenient if the user wants to use UNCRUSH to process any
archives, whether CRUSH or not. This will support any pathspecs
given, but will not support specified destination directories.
____________________________________
-l Only display a simple file list
This will replace the normal display by a simple list of files and
pathnames. This is most usefully used with -v to generate a response
file.
____________________________________
-2 Display times as 24-hour clock
This is only a cosmetic detail, but many users are firmly committed
to 12 or 24 hour clocks, in which case UNCRUSH will allow the default
12 hour clock file times to be replaced by a 24 hour clock times.
__________________________________________________________________________
Worked Examples Page 12
There are many routine archiving tasks that CRUSH could be used for. The
following selects a few that either take particular advantage of CRUSH
facilities, or that may be particularly relevant when first using CRUSH.
For simple examples see "Getting Started" at the beginning of this manual.
____________________________________
Generating a Response File for Future Backups
Most archivers allow the user to use a "response" file containing file and
path specifications to be used in addition to (or instead of) CRUSH
command-line parameters. This is convenient when a list is very large.
CRUSH allows the user to choose files for archiving on-line using the -Q
option. e.g.
CRUSH -rQv TEST *.C *.ASM >RESPLIST
This will search all subdirectories (-r), querying each file found (-Q),
but without actually creating an archive (-v). The output is directed to
the file RESPLIST. The user can then use this for future CRUSH archiving
in a command of the form:
CRUSH BACKUP @RESPLIST
____________________________________
Performing Archival Backups
CRUSH's option to backup files dated on or after a named file (not
supported by PKZIP etc.) makes it possible to create backups of all files
modified since the previous backup. This can be combined with CRUSH's
ability to automatically generate a unique filename, as follows:
BACK.BAT containing:
CRUSH -r:.LASTBAC [] *.DOC *.C *.H
IF ERRORLEVEL 1 ECHO Error occurred!
IF ERRORLEVEL 1 GOTO EXIT
REM>LASTBAC
:EXIT
The "[]" parameter replaces the normal archive name by a unique name
generated using the current date and time (e.g. 1CD29E33.ZIP, which uses
the hexadecimal value of the combined 32-bit date and time). CRUSH will
then search all subdirectories for all files matching *.DOC *.C or *.H
modified since the date and time of the file LASTBAC and add them to the
archive. If the archive step fails (e.g. out of memory etc.), the error is
reported and the command sequence ended. If successful, then "REM>LASTBAC"
will create an empty file with the current date and time for reference by
the next backup.
On the next occasion that the command "BACK" is run, CRUSH will only
search for files modified since the last backup.
__________________________________________________________________________
Worked Examples Page 13
____________________________________
Converting all Existing Archives to CRUSH
This would be a potentially mammoth task that would benefit from some
automation, unless you are willing to convert each file one-by-one. A good
choice for this task would be PocketD Plus v4.1 (D.EXE), as follows:
MD TMP
CD TMP
D .ZIP/W[PKUNZIP -d $w//CRUSH -ert $w//PAUSE//D /zd]Rq
This example converts ZIP files by running a command sequence of the
following type for each archive found:
PKUNZIP -d \C\BATS.ZIP Uncompress with subdirectories into TMP.
CRUSH -ert \C\BATS.ZIP (See below).
PAUSE Allow inspection of result.
D /zd Delete uncompressed files/dirs from TMP.
The CRUSH command compares the new CRUSH archive with the existing archive
(-e), but will not replace it unless the new archive is at least 5%
smaller (-t). The files originally compressed may also include paths, and
so CRUSH uses -r to search all uncompressed subdirectories created by the
"PKUNZIP -d" command. For those with a cautious disposition, the D.EXE
command-line includes the "q" option, allowing the user to confirm or
select each archive to be processed. The PAUSE command allows the user to
examine the output of CRUSH before the command "D /zd" deletes the files
and subdirectories temporarily uncompressed.
____________________________________
The UNDO and UNDO2 Programs
The registered version of CRUSH.EXE comes with two additional programs,
UNDO.EXE and UNDO2.EXE, which provide tiny alternatives to UNCRUSH.EXE for
unpacking an uncompressed CRUSH archive.
USAGE: UNDO crushname
UNDO2 crushname
UNDO.EXE is 3.8k and ignores any path information. UNDO2.EXE is 4.3k and
will also re-construct embedded paths. These programs can be included
within distribution archives that hold CRUSH archives, providing the
smallest package that will allow UNCRUSHing without additional programs.
Ideally UNDO.EXE and a CRU archive could be embedded inside an SFX
archive, e.g. using LHA:
CRUSH -l DEMO ! *.DOC
LHA A DEMO UNDO.EXE
LHA S DEMO
The "!" parameter above is the file "!" which contains a message displayed
when the archive DEMO.EXE is run. This can contain details of how to
uncompress the CRUSH archive, e.g. "Unpack the CRUSH archive by typing
UNDO DEMO.CRU after the DEMO.EXE executable has finished decompression."
The user may choose to rename UNDO2.EXE to UNDO.EXE or some other
convenient name. Note that distribution of CRUSH archives requires a
distribution licence (see REGISTER.DOC).
__________________________________________________________________________
Configuration Page 14
__________________________________
Configuration of CRUSH and UNCRUSH
CRUSH and UNCRUSH can be configured using environment variables, as
follows:
The CRUSH variable:
This is particularly important if you decide not to use the default
PKZIP used by CRUSH e.g.
SET CRUSH=-j
will force CRUSH to always use ARJ by default. Other options can also
be added e.g.
SET CRUSH=-jCc
will also force the normal display colour and always force a
comparison between ARJ and CRUSH when creating a CRUSH file.
The UNCRUSH variable:
This is less critical, but an example usage might be:
SET UNCRUSH=-2e
which would use the 24 hour clock and also allow UNCRUSH to be used
for uncompressing ordinary PKZIP, ARJ, LHA, ZOO, HA and UC archives.
Environment variables should be set in your AUTOEXEC.BAT, otherwise they
will be lost next time the system is re-booted.
__________________________________________________________________________
Technical Details Page 15
This information is only of interest to 3rd party developers who may want
to provide support for CRUSH archives.
__________________________________
Structure of CRUSH file (.CRU)
Address Length in Bytes Description
000000 14 CRUSH v1.3
00000E 2 Chksum
000010 2 Number of paths (only 0-255 supported)
000012 2 Number of files
000014 2 Reserved
000016 4 Totalsize of files + header length(26)
00001A "totalsize" Data
; directory held at offset "Totalsize of files + header length(26)"
000000 1 Path number
000001 1 Attribute
000002 2 Time
000004 2 Date
000006 4 Size
00000A 13 Name
000017 1 Reserved
(above repeated "Number of files" times)
; "n" Paths
path1 Each terminated by NULL
path2
..
; Archive comment
comment Terminated by NULL
__________________________________
Structure of CRUSH fast Index (.CRI)
As CRU but with Totalsize field set to 0 + Headerlen(26)
000016 4 Header length(26)
This is a Shareware copy of CRUSH v1.3
The documents MANUAL.DOC and README can be printed directly
to a conventional printer. Alternatively they can be read into
a Wordprocessor for printing using a Laser printer. If you
do this, then you should set the minimum margins that your
Wordprocessor allows, and select a 12 point Courier Font.
December 13, 2017
Add comments