Node:Ignoring Changes, Next:Speedups, Previous:Time Stamp Order, Up:Shortcomings
It would be nice to have a feature for specifying two strings, one in
from-file and one in to-file, which should be considered to
match. Thus, if the two strings are foo and bar, then if
two lines differ only in that foo in file 1 corresponds to
bar in file 2, the lines are treated as identical.
It is not clear how general this feature can or should be, or what syntax should be used for it.
A partial substitute is to filter one or both files before comparing,
e.g.:
sed 's/foo/bar/g' file1 | diff - file2
However, this outputs the filtered text, not the original.