in reply to Poor man's diff

Good code.

However, you said that you knew no way to "tell Text::Diff to ignore trailing blanks as being insignificant." I decided to explore this and found that the following code works:

#!/usr/bin/env perl die "Usage: $0 from-file to-file\n" unless @ARGV == 2; use Text::Diff; diff shift, shift, { OUTPUT => \*STDOUT, STYLE => "OldStyle", # or whatever pleases you KEYGEN => sub{ (my $line = shift) =~ s/\s*$//; return $line; }, };
In general, to compare something other than the lines themselves, just return that from the KEYGEN argument. For example, inserting sub{return substr shift, 0, 1} compares only the first characters. Unfortunately, the documentation for this is hidden in Algorithm::Diff.