DIFFMK(1) General Commands Manual DIFFMK(1)
diffmk - mark differences between versions of a troff input file
diffmk oldfile newfile markedfile
This command is available with the Text software installation option.
Refer to for information on how to install optional software.
diffmk compares two versions of a file and creates a third version that
includes "change mark" (.mc) commands for nroff(1) and troff(1). old-
file and newfile are the old and new versions of the file. diffmk gen-
erates markedfile, which, contains the text from newfile with troff(1)
"change mark" requests (.mc) inserted where newfile differs from old-
file. 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 *.
diffmk can also be used in conjunction with the proper troff requests
to produce program listings with marked changes. In the following com-
diffmk old.c new.c marked.c ; nroff reqs marked.c | pr
the file reqs contains the following troff requests:
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(1V) to globally change them.
diff(1), nroff(1), sed(1V), troff(1)
Aesthetic considerations may dictate manual adjustment of some output.
File differences involving only formatting requests may produce unde-
sirable output, that is, replacing .sp by .sp 2 will produce a "change
mark" on the preceding or following line of output.
18 January 1988 DIFFMK(1)