BasUpd 2.0 adds commands from PDS and
Visual Basic to QuickBASIC. Library and
full sources included. By Tom Hanlin.

BASUPD Copyright (c) 1992-1994 Thomas G. Hanlin III

BasUpd Library, v2.0

for QuickBASIC 4.0 - 4.5



This library provides a set of routines which mimic new
commands in other Microsoft BASIC compilers, such as PDS 7.x
and Visual Basic. In effect, it updates your QuickBASIC
compiler to take advantage of these new features. This adds a
little more life to good ol' QuickBASIC and keeps you in touch
with the ever-evolving BASIC language.

The included libraries are made for QuickBASIC 4.5. If you are
using one of the QuickBASIC 4.0, 4.0a, 4.0b releases, you must
recompile the .BAS files and recreate the libraries.

The BasUpd library is protected by copyright. However, it may
be distributed freely, provided that all files are included
together in original condition-- that is, you may not add
files, remove files, or alter files in the BasUpd library.

BasUpd routines may be used in your program without royalties
or licensing fees of any kind.

If you find BasUpd useful, you may want to check out my other
free and shareware products for BASIC languages. These include
a wide assortment of libraries, utilities, and other goodies.
See the CATALOG.TXT and ORDER.FRM files for more information.

Using BasUpd



BasUpd is a library of BASIC and assembly language routines.
To use BasUpd, you must start QB with the /L switch, telling it
to load the BasUpd library. For example:

QB program.bas /L BASUPD

or

QB /L BASUPD

If you compile from the command line, using BC, you must tell
LINK to bring in the necessary routines from the BASUPD
library. For example:

BC program.bas/O;
LINK program.obj/EX,,NUL,BASUPD

You also need to include a "metacommand" in your program which
loads the DECLARE information for the functions. The first
line in your program should read something like this:

REM $INCLUDE: 'BASUPD.BI'

That's really all there is to it. Once loaded, these routines
act just like part of the BASIC language.

The BasUpd library provides you with almost all of the new
BASIC functions from PDS 7.x and Visual Basic. They are made
to work as closely as possible to "the real thing". This
applies quite specifically to the time/date routines, which
return the same "serial number" value as the equivalent PDS/VB
routines. So, if you move to one of these compilers, you will
be able to use its functions instead of those in BasUpd with a
minimum of fuss.

Name: ChDrive

This routine allows you to change the default drive. The drive
letter may be either uppercase or lowercase. Only the first
character of the string is examined, so it doesn't matter if
you use a colon for the drive spec.

ChDrive Drive$



Name: CurDir$

This function returns the default subdirectory on the specified
drive. The drive letter may be either uppercase or lowercase.
Only the first character of the string is examined, so it
doesn't matter if you use a colon for the drive spec. If you
just want to specify the current drive, you can use a null
string for the drive spec.

Subdir$ = CurDir$("C:")

The result is a fully-specified path. For instance, the above
example might have returned something like "C:\BASUPD".



Name: DateSerial#

This function returns a "serial number" for a specified date.
See the appendix for a discussion of time/date serial numbers.

You may specify the year as 1753-2078, or as 0-178 (where 0 is
assumed to mean 1900, and so forth). It might be wise to
restrict that to 0-99 instead of 0-178; while Microsoft's docs
say that 0-178 works, their version actually generates an error
if 100-178 is used. The BasUpd version accepts the full 0-178
range.

Serial# = DateSerial#(YearNr%, MonthNr%, DayNr%)

Please note the unusual order of the parameters. Also, be
careful not to use "Year", "Month", or "Day" as variable names,
since these are reserved words providing other time/date
functions.



Name: Day%

This function returns the day corresponding to a specified
time/date serial number.

DayNr% = Day%(Serial#)

Name: Error$

This function returns the error message associated with a
specific error number. This would most often be used as part
of an error-trapping routine. Note that the built-in BASIC
function ERR tells you the current error number.

ErrorMsg$ = Error$(ErrorNumber%)



Name: Hour%

This function returns the hour corresponding to a specific
time/date serial number.

HourNr% = Hour%(Serial#)



Name: Minute%

This function returns the minute corresponding to a specific
time/date serial number.

MinuteNr% = Minute%(Serial#)



Name: Month%

This function returns the month corresponding to a specific
time/date serial number.

MonthNr% = Month%(Serial#)



Name: Now%

This function returns a time/date serial number for the current
time and date.

Serial# = Now%

Name: Second%

This function returns the second corresponding to a specific
time/date serial number.

SecondNr% = Second%(Serial#)



Name: TimeSerial#

This function returns a "serial number" for a specified time.
See the appendix for a discussion of time/date serial numbers.

The hour is specified using 24-hour (military) time, with a
range of 0-23 (midnight-11pm).

Serial# = TimeSerial#(HourNr%, MinuteNr%, SecondNr%)

Be careful not to use "Hour", "Minute", or "Second" as variable
names, since these are reserved words providing other time/date
functions.



Name: WeekDay%

This function returns the day of the week corresponding to a
specific time/date serial number. This is returned as a number
1-7, where 1 = Sunday, 2 = Monday, ..., 7 = Saturday.

WeekDayNr% = WeekDay%(Serial#)



Name: Year%

This function returns the year corresponding to a specific
time/date serial number.

YearNr% = Year%(Serial#)

Appendix A

Time/Date Serial Numbers



The new time and date routines are based on an encoded value
called a "serial number" (Microsoft's choice, not mine). This
is a double-precision floating point value which may include
either time or date information, or both.

To decode a serial number, divide it into left and right parts
at the decimal point. The part to the left of the decimal
represents the date. The part to the right of the decimal
gives the time.

The date is specified in days, based on December 30, 1899.
Dates before then will be negative. Dates after then will be
positive. Years from 1753-2078 are supported.

The time is specified as a number indicating how much of the
day has been used. The easiest way to calculate it is to
convert the time to the number of seconds past midnight:

TimeNow# = (HourNr * 60 + MinuteNr) * 60 + SecondNr

Divide this by the number of seconds in a day (86,400), and
you've got the same number as used in a time/date serial
number.

The approach used to creating a time/date serial number means
that you can use these numbers for comparison or sorting: a
larger serial number will always indicate a later time/date
than a smaller serial number. Date manipulation is also
possible by adding/subtracting days from the serial number,
etc. Date validation can be accomplished by converting a date
to a serial number and back, then comparing the resulting
year/month/day to the original.