commit cbb6e9737495f701577b95d7a1fdf8a6fed26048
parent 34146ad1805c9fdae46d62482e18d52932938ca2
Author: Ed van Bruggen <edvb54@gmail.com>
Date: Mon, 25 Jul 2016 22:04:15 -0700
Git: Use diff-highlight script as pager
Diffstat:
2 files changed, 220 insertions(+), 0 deletions(-)
diff --git a/bin/diff-highlight b/bin/diff-highlight
@@ -0,0 +1,218 @@
+#!/usr/bin/perl
+
+use 5.008;
+use warnings FATAL => 'all';
+use strict;
+
+# Highlight by reversing foreground and background. You could do
+# other things like bold or underline if you prefer.
+my @OLD_HIGHLIGHT = (
+ color_config('color.diff-highlight.oldnormal'),
+ color_config('color.diff-highlight.oldhighlight', "\x1b[7m"),
+ color_config('color.diff-highlight.oldreset', "\x1b[27m")
+);
+my @NEW_HIGHLIGHT = (
+ color_config('color.diff-highlight.newnormal', $OLD_HIGHLIGHT[0]),
+ color_config('color.diff-highlight.newhighlight', $OLD_HIGHLIGHT[1]),
+ color_config('color.diff-highlight.newreset', $OLD_HIGHLIGHT[2])
+);
+
+my $RESET = "\x1b[m";
+my $COLOR = qr/\x1b\[[0-9;]*m/;
+my $BORING = qr/$COLOR|\s/;
+
+my @removed;
+my @added;
+my $in_hunk;
+
+# Some scripts may not realize that SIGPIPE is being ignored when launching the
+# pager--for instance scripts written in Python.
+$SIG{PIPE} = 'DEFAULT';
+
+while (<>) {
+ if (!$in_hunk) {
+ print;
+ $in_hunk = /^$COLOR*\@/;
+ }
+ elsif (/^$COLOR*-/) {
+ push @removed, $_;
+ }
+ elsif (/^$COLOR*\+/) {
+ push @added, $_;
+ }
+ else {
+ show_hunk(\@removed, \@added);
+ @removed = ();
+ @added = ();
+
+ print;
+ $in_hunk = /^$COLOR*[\@ ]/;
+ }
+
+ # Most of the time there is enough output to keep things streaming,
+ # but for something like "git log -Sfoo", you can get one early
+ # commit and then many seconds of nothing. We want to show
+ # that one commit as soon as possible.
+ #
+ # Since we can receive arbitrary input, there's no optimal
+ # place to flush. Flushing on a blank line is a heuristic that
+ # happens to match git-log output.
+ if (!length) {
+ local $| = 1;
+ }
+}
+
+# Flush any queued hunk (this can happen when there is no trailing context in
+# the final diff of the input).
+show_hunk(\@removed, \@added);
+
+exit 0;
+
+# Ideally we would feed the default as a human-readable color to
+# git-config as the fallback value. But diff-highlight does
+# not otherwise depend on git at all, and there are reports
+# of it being used in other settings. Let's handle our own
+# fallback, which means we will work even if git can't be run.
+sub color_config {
+ my ($key, $default) = @_;
+ my $s = `git config --get-color $key 2>/dev/null`;
+ return length($s) ? $s : $default;
+}
+
+sub show_hunk {
+ my ($a, $b) = @_;
+
+ # If one side is empty, then there is nothing to compare or highlight.
+ if (!@$a || !@$b) {
+ print @$a, @$b;
+ return;
+ }
+
+ # If we have mismatched numbers of lines on each side, we could try to
+ # be clever and match up similar lines. But for now we are simple and
+ # stupid, and only handle multi-line hunks that remove and add the same
+ # number of lines.
+ if (@$a != @$b) {
+ print @$a, @$b;
+ return;
+ }
+
+ my @queue;
+ for (my $i = 0; $i < @$a; $i++) {
+ my ($rm, $add) = highlight_pair($a->[$i], $b->[$i]);
+ print $rm;
+ push @queue, $add;
+ }
+ print @queue;
+}
+
+sub highlight_pair {
+ my @a = split_line(shift);
+ my @b = split_line(shift);
+
+ # Find common prefix, taking care to skip any ansi
+ # color codes.
+ my $seen_plusminus;
+ my ($pa, $pb) = (0, 0);
+ while ($pa < @a && $pb < @b) {
+ if ($a[$pa] =~ /$COLOR/) {
+ $pa++;
+ }
+ elsif ($b[$pb] =~ /$COLOR/) {
+ $pb++;
+ }
+ elsif ($a[$pa] eq $b[$pb]) {
+ $pa++;
+ $pb++;
+ }
+ elsif (!$seen_plusminus && $a[$pa] eq '-' && $b[$pb] eq '+') {
+ $seen_plusminus = 1;
+ $pa++;
+ $pb++;
+ }
+ else {
+ last;
+ }
+ }
+
+ # Find common suffix, ignoring colors.
+ my ($sa, $sb) = ($#a, $#b);
+ while ($sa >= $pa && $sb >= $pb) {
+ if ($a[$sa] =~ /$COLOR/) {
+ $sa--;
+ }
+ elsif ($b[$sb] =~ /$COLOR/) {
+ $sb--;
+ }
+ elsif ($a[$sa] eq $b[$sb]) {
+ $sa--;
+ $sb--;
+ }
+ else {
+ last;
+ }
+ }
+
+ if (is_pair_interesting(\@a, $pa, $sa, \@b, $pb, $sb)) {
+ return highlight_line(\@a, $pa, $sa, \@OLD_HIGHLIGHT),
+ highlight_line(\@b, $pb, $sb, \@NEW_HIGHLIGHT);
+ }
+ else {
+ return join('', @a),
+ join('', @b);
+ }
+}
+
+sub split_line {
+ local $_ = shift;
+ return utf8::decode($_) ?
+ map { utf8::encode($_); $_ }
+ map { /$COLOR/ ? $_ : (split //) }
+ split /($COLOR+)/ :
+ map { /$COLOR/ ? $_ : (split //) }
+ split /($COLOR+)/;
+}
+
+sub highlight_line {
+ my ($line, $prefix, $suffix, $theme) = @_;
+
+ my $start = join('', @{$line}[0..($prefix-1)]);
+ my $mid = join('', @{$line}[$prefix..$suffix]);
+ my $end = join('', @{$line}[($suffix+1)..$#$line]);
+
+ # If we have a "normal" color specified, then take over the whole line.
+ # Otherwise, we try to just manipulate the highlighted bits.
+ if (defined $theme->[0]) {
+ s/$COLOR//g for ($start, $mid, $end);
+ chomp $end;
+ return join('',
+ $theme->[0], $start, $RESET,
+ $theme->[1], $mid, $RESET,
+ $theme->[0], $end, $RESET,
+ "\n"
+ );
+ } else {
+ return join('',
+ $start,
+ $theme->[1], $mid, $theme->[2],
+ $end
+ );
+ }
+}
+
+# Pairs are interesting to highlight only if we are going to end up
+# highlighting a subset (i.e., not the whole line). Otherwise, the highlighting
+# is just useless noise. We can detect this by finding either a matching prefix
+# or suffix (disregarding boring bits like whitespace and colorization).
+sub is_pair_interesting {
+ my ($a, $pa, $sa, $b, $pb, $sb) = @_;
+ my $prefix_a = join('', @$a[0..($pa-1)]);
+ my $prefix_b = join('', @$b[0..($pb-1)]);
+ my $suffix_a = join('', @$a[($sa+1)..$#$a]);
+ my $suffix_b = join('', @$b[($sb+1)..$#$b]);
+
+ return $prefix_a !~ /^$COLOR*-$BORING*$/ ||
+ $prefix_b !~ /^$COLOR*\+$BORING*$/ ||
+ $suffix_a !~ /^$BORING*$/ ||
+ $suffix_b !~ /^$BORING*$/;
+}
diff --git a/gitconfig b/gitconfig
@@ -26,6 +26,8 @@
A = add -A .
c = commit
p = push
+[pager]
+ diff = diff-highlight | less
[credential]
helper = cache --timeout=43200
