grep: color patterns in output

Coloring matches makes them easier to spot in the output.

Add two options and two parameters: color.grep (to turn coloring on
or off), color.grep.match (to set the color of matches), --color
and --no-color (to turn coloring on or off, respectively).

The output of external greps is not changed.

This patch is based on earlier ones by Nguyễn Thái Ngọc Duy and
Thiago Alves.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/builtin-grep.c b/builtin-grep.c
index 3f12ba3826..e2c0f01616 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -22,6 +22,24 @@
 
 static int builtin_grep;
 
+static int grep_config(const char *var, const char *value, void *cb)
+{
+	struct grep_opt *opt = cb;
+
+	if (!strcmp(var, "grep.color") || !strcmp(var, "color.grep")) {
+		opt->color = git_config_colorbool(var, value, -1);
+		return 0;
+	}
+	if (!strcmp(var, "grep.color.match") ||
+	    !strcmp(var, "color.grep.match")) {
+		if (!value)
+			return config_error_nonbool(var);
+		color_parse(value, var, opt->color_match);
+		return 0;
+	}
+	return git_color_default_config(var, value, cb);
+}
+
 /*
  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  * pathname wildcards are allowed.
@@ -536,6 +554,12 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	opt.pattern_tail = &opt.pattern_list;
 	opt.regflags = REG_NEWLINE;
 
+	strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
+	opt.color = -1;
+	git_config(grep_config, &opt);
+	if (opt.color == -1)
+		opt.color = git_use_color_default;
+
 	/*
 	 * If there is no -- then the paths must exist in the working
 	 * tree.  If there is no explicit pattern specified with -e or
@@ -732,6 +756,14 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			opt.relative = 0;
 			continue;
 		}
+		if (!strcmp("--color", arg)) {
+			opt.color = 1;
+			continue;
+		}
+		if (!strcmp("--no-color", arg)) {
+			opt.color = 0;
+			continue;
+		}
 		if (!strcmp("--", arg)) {
 			/* later processing wants to have this at argv[1] */
 			argv--;