diffmk - Marks differences between files
diffmk [-b] [-ab'mark'] [-ae'mark'] [-cb'mark'] [-ce'mark'] [-db'mark']
[-de'mark'] file1 file2
The diffmk command compares two versions of a file and creates a new file
that marks the differences.
Uses mark to mark where added lines begin.
Uses mark to mark where added lines end.
-b Ignores differences that are only changes in tabs or spaces on a line.
Uses mark to mark where changed lines begin.
Uses mark to mark where changed lines end.
Uses mark to mark where deleted lines begin.
Uses mark to mark where deleted lines end.
The file1 and file2 variables are the old and new versions of the file,
respectively. The diffmk command compares them and writes a new version to
standard output, which can be redirected to a file. This output contains
the lines of file2 marked with nroff change mark requests (.mc), or with
the marks you specify with the -ab, -ae, -cb, -ce, -db, and -de options.
When output containing .mc requests is formatted with nroff, changed or
inserted lines are marked by a | (vertical bar) at the right margin of each
line. An * (asterisk) indicates that a line was deleted.
If the DIFFMARK environment variable is defined, it names a command string
that diffmk uses to compare the files. (Normally, diffmk uses the diff
command.) For example, you might set DIFFMARK to diff -h in order to
better handle extremely large files.
1. To mark the differences between two versions of a text file, enter:
diffmk -ab'>>I:' -ae'<<I' -cb'>>C' -ce'<<C' -db'>>D' -de'<<D' \
chap1.old chap1 >>chap1.diffs
This causes diffmk to create a copy of chap1 called chap1.diffs, show-
ing differences between chap1.old and chap1. Additions of one or more
lines are marked with >>I and <<I, changed lines are marked with >>C and
<<C, and deletions are marked with >>D and <<D.
2. To mark differences with nroff requests, enter:
diffmk chap1.old chap1 >> chap1.nroff
This produces a copy of chap1 called chap1.nroff containing nroff
change mark requests to identify text that was added to, changed, or
deleted from chap1.old.
3. To use different nroff marking requests and ignore changes in white
diffmk -b -cb'.mc %' chap1.old chap1 >> chap1.nroff
This imbeds commands that mark changes with % (percent sign), addi-
tions with | (the default, because no -a option is specified), and
deletions with * (the default). It does not mark changes that only
involve a different number of spaces or tabs between words (-b).
Commands: diff(1), nroff(1)