--- /usr/bin/colordiff	2009-04-29 09:56:04.000000000 +0200
+++ /home/manu/bin/colordiff	2013-03-29 12:27:34.789423159 +0100
@@ -141,9 +141,20 @@
     }
 }
 
-# If output is to a file, switch off colours, unless 'color_patch' is set
-# Relates to http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=378563
-if ((-f STDOUT) && ($color_patch == 0)) {
+# We explicitly close STDOUT always.
+END { close(STDOUT) || die "can't close stdout: $!" }
+
+
+my $use_color ="auto";
+
+my $specified_difftype;
+GetOptions(
+    "difftype=s" => \$specified_difftype,
+    "color:s" => \$use_color
+);
+
+if (($use_color eq 'auto' and (!(-t STDOUT) && ($color_patch == 0)))
+    or ($use_color eq 'never' or $use_color eq 'no')) {
     $plain_text  = '';
     $file_old    = '';
     $file_new    = '';
@@ -151,12 +162,18 @@
     $cvs_stuff   = '';
     $plain_text  = '';
     $colour{off} = '';
+} elsif ($use_color eq 'auto' 
+         or $use_color eq 'yes' or $use_color eq 'always') {
+    # Nothing to do
+} else {
+    print STDERR "Unknown value for option '--color': $use_color\n";
+    print STDERR "Valid options are:\n".
+    "      --color[=WHEN],\n".
+    "      --colour[=WHEN]  use markers to highlight the matching strings;\n".
+    "                       WHEN is `always', `never', or `auto'\n";
+    exit(1);
 }
 
-my $specified_difftype;
-GetOptions(
-    "difftype=s" => \$specified_difftype
-);
 # TODO - check that specified type is valid, issue warning if not
 
 # ----------------------------------------------------------------------------
@@ -166,6 +183,13 @@
     print STDERR "$copyright $author, $author_email\n\n";
 }
 
+# If output is to a file, switch off colours, unless 'color_patch' is set
+# Relates to http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=378563
+if (-t STDOUT) {
+    my  $pager = $ENV{PAGER} || "less -r";
+    print $pager."\n";
+    open(STDOUT, "| $pager") or die "can't fork a pager: $!";
+}
 # FIXME - work out some magic here to make it rip off
 # colordiff-specific long options, such as:
 #