DIFFMK(1)
NAME
diffmk − mark differences between files
SYNOPSIS
diffmk name1 name2 name3
DESCRIPTION
Diffmk compares two versions of a file and creates a third file that includes “change mark” commands for nroff(1) or troff(1). Name1 and name2 are the old and new versions of the file. Diffmk 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 ∗.
If anyone is so inclined, he can use diffmk to produce listings of C (or other) programs with changes marked. A typical command line for such use is:
diffmk old.c new.c tmp; nroff macs tmp │ pr
where the file macs contains:
.pl 1
.ll 77
.nf
.eo
.nc `
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 diffmk can be edited to change them (diffmk is a shell procedure).
SEE ALSO
BUGS
Aesthetic considerations may dictate manual adjustment of some output. File differences involving only formatting requests may produce undesirable output, i.e., replacing .sp by .sp 2 will produce a “change mark” on the preceding or following line of output.