[makecheck]

I handle this in a way that is more agnostic to the type of revision control, and fully flexible in coloring (using the most powerful scheme available).

For example, I shouldn't have to put up with basic colors if the terminal can do better.

Here is how it works; starting with:

  #!/bin/bash 
  if [ -r ".svn" ] ; then
    exec svn diff ${1+"$@"} | my_colorize_diff
  else
    git diff ${1+"$@"} | my_colorize_diff
  fi

...where the "my_colorize_diff" script at the end of the pipe is as follows:

  #!/usr/bin/env perl
  # by Kevin Grant ([e-mail])
  my $term_program = (exists $ENV{'TERM_PROGRAM'} && defined $ENV{'TERM_PROGRAM'}) ? $ENV{'TERM_PROGRAM'} : '';
  my $term = (exists $ENV{'TERM'} && defined $ENV{'TERM'}) ? $ENV{'TERM'} : 'vt100';
  my $is_xterm = ($term =~ /xterm/);
  my $is_24bit = ($term_program =~ /MacTerm/);
  print "\033#3BEGIN DIFF\n";
  print "\033#4BEGIN DIFF\n\033#5";
  while (<>) {
    if (/^\+/ && !/^\+\+/) {
      if ($is_24bit) {
        print "\033[48:2:150:200:150m", "\033[2K", "\033[38:2::88:m", "\033[1m";
      } elsif ($is_xterm) {
        print "\033[48;5;149m", "\033[2K", "\033[38;5;235m", "\033[1m";
      } else {
        print "\033[42m", "\033[2K", "\033[30m", "\033[1m";
      }
    } elsif (/^\-/ && !/^\-\-/) {
      if ($is_24bit) {
        print "\033[48:2:244:150:150m", "\033[2K", "\033[38:2:144:0::m";
      } elsif ($is_xterm) {
        print "\033[48;5;52m", "\033[2K", "\033[38;5;124m";
      } else {
        print "\033[41m", "\033[2K", "\033[37m";
      }
    } else {
      print "\033[3m";
    }
    chomp;
    print;
    print "\033[0m\n";
  }
  print "\033#3END DIFF\n";
  print "\033#4END DIFF\n\033#5";

[thristian]

For what it's worth, there's a lot of 24-bit-capable terminals that aren't MacTerm. Even xterm supports the 24-bit-color sequences, although it picks the closest entry in its 256-colour palette rather than using the 24-bit colour directly.

Also, you seem to be assuming "xterm" supports 256 colours and everything else doesn't. The best way to figure out how many colours the terminal supports is $(tput colours). tput also looks up other useful sequences; you can "tput bold" to turn on bold mode, "tput setaf 12" to set the foreground to colour 12 (bright yellow), "tput sgr0" to zero all active formatting, etc.

[makecheck]

Good point. Although, unless there are shells that have "tput" built-in, that means more subprocesses to obtain basic information (which would slow down the result a bit). In my case, the environment is sufficient to figure out what to do.