DIFFMK(1) User Commands DIFFMK(1)


diffmk - mark differences between versions of a troff input file


diffmk oldfile newfile markedfile


diffmk compares two versions of a file and creates a third version that
includes "change mark" (.mc) commands for nroff(1) and troff(1). oldfile
and newfile are the old and new versions of the file. diffmk generates
markedfile, which, contains the text from newfile with troff(1) "change
mark" requests (.mc) inserted where newfile differs from oldfile. When
markedfile is formatted, changed or inserted text is shown by | at the
right margin of each line. The position of deleted text is shown by a
single *.


See largefile(7) for the description of the behavior of diffmk when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).


Example 1: An example of the diffmk command.

diffmk can also be used in conjunction with the proper troff requests to
produce program listings with marked changes. In the following command

example% diffmk old.c new.c marked.c ; nroff reqs marked.c | pr

the file reqs contains the following troff requests:

.pl 1
.ll 77

which eliminate page breaks, adjust the line length, set no-fill mode,
ignore escape characters, and turn off hyphenation, respectively.

If the characters | and * are inappropriate, you might run markedfile
through sed(1) to globally change them.


diff(1), nroff(1), sed(1), troff(1), attributes(7), largefile(7)


Aesthetic considerations may dictate manual adjustment of some output.
File differences involving only formatting requests may produce
undesirable output, that is, replacing .sp by .sp 2 will produce a
"change mark" on the preceding or following line of output.

September 14, 1992 DIFFMK(1)