diffmk(1)diffmk(1)Namediffmk - mark differences between files
Syntaxdiffmk name1 name2 name3
The command compares two versions of a file and creates a third file
that includes ``change mark'' commands for or The name1 and name2 are
the old and new versions of the file. The command generates name3,
which contains the lines of name2 plus inserted formatter ``change
mark'' (.mc) requests. When name3 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 ∗.
The command can be used to produce listings of C (or other) programs
with changes marked. A typical command line for such use is the fol‐
diffmk old.c new.c tmp; nroff macs tmp ⎪ pr
In this example the file macs contains:
The .ll request might specify a different line length, depending on the
nature of the program being printed. The .eo and .nc requests are
probably needed only for C programs.
If the characters ⎪ and ∗ are inappropriate, a copy of can be edited to
change them. The command is a shell procedure.
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.
See Alsocmp(1), comm(1), diff(1), nroff(1), join(1), sccsdiff(1), troff(1),