git config --get-colorbool

This adds an option to help scripts find out color settings from
the configuration file.

    git config --get-colorbool color.diff

inspects color.diff variable, and exits with status 0 (i.e. success) if
color is to be used.  It exits with status 1 otherwise.

If a script wants "true"/"false" answer to the standard output of the
command, it can pass an additional boolean parameter to its command
line, telling if its standard output is a terminal, like this:

    git config --get-colorbool color.diff true

When called like this, the command outputs "true" to its standard output
if color is to be used (i.e. "color.diff" says "always", "auto", or
"true"), and "false" otherwise.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 40 insertions, 1 deletions

diff --git a/builtin-config.c b/builtin-config.c
index 6175dc3738..d10b03f50c 100644
--- a/builtin-config.c
+++ b/builtin-config.c
@@ -3,7 +3,7 @@
 #include "color.h"
 
 static const char git_config_set_usage[] =
-"git-config [ --global | --system | [ -f | --file ] config-file ] [ --bool | --int ] [ -z | --null ] [--get | --get-all | --get-regexp | --replace-all | --add | --unset | --unset-all] name [value [value_regex]] | --rename-section old_name new_name | --remove-section name | --list | --get-color var [default]";
+"git-config [ --global | --system | [ -f | --file ] config-file ] [ --bool | --int ] [ -z | --null ] [--get | --get-all | --get-regexp | --replace-all | --add | --unset | --unset-all] name [value [value_regex]] | --rename-section old_name new_name | --remove-section name | --list | --get-color var [default] | --get-colorbool name [stdout-is-tty]";
 
 static char *key;
 static regex_t *key_regexp;
@@ -208,6 +208,43 @@ static int get_color(int argc, const char **argv)
 	return 0;
 }
 
+static int stdout_is_tty;
+static int get_colorbool_found;
+static int git_get_colorbool_config(const char *var, const char *value)
+{
+	if (!strcmp(var, get_color_slot))
+		get_colorbool_found =
+			git_config_colorbool(var, value, stdout_is_tty);
+	return 0;
+}
+
+static int get_colorbool(int argc, const char **argv)
+{
+	/*
+	 * git config --get-colorbool <slot> [<stdout-is-tty>]
+	 *
+	 * returns "true" or "false" depending on how <slot>
+	 * is configured.
+	 */
+
+	if (argc == 2)
+		stdout_is_tty = git_config_bool("command line", argv[1]);
+	else if (argc == 1)
+		stdout_is_tty = isatty(1);
+	else
+		usage(git_config_set_usage);
+	get_colorbool_found = 0;
+	get_color_slot = argv[0];
+	git_config(git_get_colorbool_config);
+
+	if (argc == 1) {
+		return get_colorbool_found ? 0 : 1;
+	} else {
+		printf("%s\n", get_colorbool_found ? "true" : "false");
+		return 0;
+	}
+}
+
 int cmd_config(int argc, const char **argv, const char *prefix)
 {
 	int nongit = 0;
@@ -283,6 +320,8 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 			return 0;
 		} else if (!strcmp(argv[1], "--get-color")) {
 			return get_color(argc-2, argv+2);
+		} else if (!strcmp(argv[1], "--get-colorbool")) {
+			return get_colorbool(argc-2, argv+2);
 		} else
 			break;
 		argc--;