git-log-describe: add git-describe output to git-log

As of today (2013-11-22) there is still no support for adding an
indication of tag to the output of git log. This script post-processes
the output of `git log` and adds the output of `git describe
--first-parent` to line following the commit ID.

For a version suitable for `git log --oneline`, see [1].

 [1]: http://stackoverflow.com/q/17379010/427545

1 files changed, 34 insertions, 0 deletions

diff --git a/git-log-describe.awk b/git-log-describe.awk
new file mode 100755
index 0000000..0ac233e
--- /dev/null
+++ b/git-log-describe.awk
@@ -0,0 +1,34 @@
+#!/usr/bin/awk -f
+# Adds a "git describe" (nearest tag) output for `git log` (with support for
+# color escapes and --graph markers). --oneline is not supported.
+#
+# Copyright (c) 2013 Peter Wu <lekensteyn@gmail.com>
+# Licensed under GPLv3 or any latter version
+
+function has_color(str) {
+	if (str ~ /\033/) return 1;
+
+	return 0;
+}
+
+{ print; }
+
+{
+	is_color = has_color($0);
+	# strip color escapes for easier text matching
+	gsub(/\033\[[0-9]*m/, "");
+
+	text_len = length($0);
+	# remove --graph markers
+	sub(/^[*|][*|_/\\ ]*/, "");
+	indent_len = length($0) - text_len;
+}
+
+$1 == "commit" && $2 ~ /^[0-9a-f]{5,40}$/ {
+	hash = $2;
+
+	printf("%" indent_len "sDescribe: ", "");
+	if (is_color) printf("\033[96m"); # light cyan
+	system("git describe --first-parent " hash);#  " |tr -d '\''\n'\''");
+	if (is_color) printf("\033[m");
+}