Dec 062017
This program displays two files simultaneously on the screen.
File DUALLIST.ZIP from The Programmer’s Corner in
Category Word Processors
This program displays two files simultaneously on the screen.
File Name File Size Zip Size Zip Type
DL.DOC 5948 2647 deflated
DL.EXE 19645 11726 deflated

Download File DUALLIST.ZIP Here

Contents of the DL.DOC file

DL -- Double Lister, version 1.02, for IBM PC/XT/AT under PC- or MS-DOS

This command displays two files simultaneously on the screen:

DL {d:}{\path\}file1{.ext} {d:}{\path\}{file2}{.ext}

Both files must be given. If you omit one or both, you will be prompted for
them. Full pathnames are accepted. You may abbreviate the second file:
1. use '*' in place of filename or ext (or both), OR
2. give d: or \path\ (or both) and omit the filename.ext altogether.
In either case, the missing parts will be supplied from the first file.
(Note: fullblown wildcards are not supported.)

The files will be displayed initially as text in two horizontal windows, with
the first file in the upper window designated as "active". The active file's
name is displayed in reverse video.


* Strike Esc or Q to leave the program.


* Strike + to make the second file active; - to make the first file active.

* Strike L (or Scroll Lock) to enter or leave Lockstep mode. In Lockstep mode,
both files are active; i.e., scroll simultaneously. The letter L will appear in
the lower right corner of the screen to remind you of the status of Lockstep.
Lockstep is very useful for comparing files that are almost alike.


* To scroll the active file up or down, use PgUp, PgDn, Up Arrow or Down Arrow.
Strike Home to go the top of the file, End to go to the bottom (but see
Limitations, below).

* If you have long lines, you can scroll right or left 20 columns at a time
using Left Arrow and Right Arrow, or one column at a time using Ctrl Left Arrow
and Ctrl Right Arrow. Ctrl Home will return to the left margin. The column
number will be displayed near the file name.


* Strike V to change to a vertical (side-by-side, columnar) display; H to
change back to horizontal. Strike V repeatedly when the display is already
vertical to make the left window wider, narrower, or the same as the right.
Strike H repeatedly when the display is already horizontal to make the upper
window taller, shorter, or the same as the lower.

* Strike X to enter or leave hexadecimal display mode for the active files. If
the display is horizontal, sixteen characters will be shown on each line; if
vertical, eight. The hexadecimal address within the file of the first byte
shown is displayed next to the file name. End of file is not detected in this
mode; you are not prevented from scrolling (harmlessly) off the end of file.

* Strike 7 to enter 7-bit display mode. In this mode, the high-order bit of
each character is set zero, and control characters other than new-line are
omitted from the display. 7-bit mode may be set any time, but is suspended
while hexadecimal mode is in effect. This mode is useful for viewing files
created by some word processors.

* Strike 8 to leave 7-bit display mode.


* Strike F to find the next occurrence of a string within a line. You will be
prompted for a string. Searching is case-sensitive, so enter the exact desired
string. The search begins with the second line currently displayed. To search
again for the same string, simply press Enter when prompted for the string. In
Lockstep mode, both files will be scrolled until the string is found in either
file. F has no effect in hexadecimal display mode.

* Strike D to locate the next difference between the files. Comparison begins
with the second line of each window, and proceeds until a difference is found
or the end of either file is reached. The first lines to differ are displayed
at the top of the windows. You may then strike D again immediately, or scroll
one file to line them up before striking D again. While comparison is in
progress, the letter D will blink in the lower right corner of the screen.
D has no effect in hexadecimal display mode.

* Limitation: uses direct video memory display. Works only on IBM mono or CGA
or exact compatible.

* Limitation: the combined size of both files is limited to available memory.
If the files are larger, only part of them will be displayed, up to a maximum
of about 128k each. In that case, the End key travels only to the end of the
buffer, not to the true end of file. The first file has priority on available
memory, so if you have a big and a little file, enter the little one first.

Written by Stephen S. Bates in Microsoft C v4.0 in October 1987. This is
shareware. Permission to copy this program is hereby granted with the
following conditions: you must distribute DL.EXE and DL.DOC (this file)
together and unmodified; you must not charge more than a nominal distribution
fee (maximum $6.00) for a diskette containing the files; you may not
distribute DL with or as part of other commercially sold software without
written permission of the author. In short, you are not permitted to sell this
program for profit in any way, shape or form.

If you like this program and use it regularly, the author would appreciate a
contribution of $15.00, sent to the address below. As with all shareware,
these contributions are the incentives for authors to continue distributing
quality software in this manner. Only contributors' questions or suggestions
of features for future revisions will be considered; others will not. Whether
or not you contribute, the author would appreciate being informed of any
actual bugs:

Stephen S. Bates
3510 Gramercy
Houston, TX 77025
(713) 665-5817

Thank you.

Revision history:
1.01 11/87 fixed minor bugs; added D feature; made reading of files quicker.
1.02 12/87 added unequal window sizes feature for H,V;
added heX,Find,End,^Left ^Right ^Home, 7/8;
allowed abbreviated second filename;
made reading of files still quicker;
changed to Microsoft C 5.0 .

 December 6, 2017  Add comments

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