color: disable color when json output is requested

Instead of declaring -color and -json exclusive, ignore -color when
-json is provided. The rationale is to allow to put -color in an alias
for ip while still being able to use -json. -color is merely a
presentation suggestion and we can assume there is nothing to color in
the JSON output.

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

include/color.h

@@ -13,7 +13,6 @@ enum color_attr {
 };
 
 void enable_color(void);
-void check_if_color_enabled(void);
 void set_color_palette(void);
 int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...);
 enum color_attr ifa_family_color(__u8 ifa_family);

ip/ip.c

@@ -172,6 +172,7 @@ int main(int argc, char **argv)
 {
 	char *basename;
 	char *batch_file = NULL;
+	int color = 0;
 
 	basename = strrchr(argv[0], '/');
 	if (basename == NULL)
@@ -269,7 +270,7 @@ int main(int argc, char **argv)
 			}
 			rcvbuf = size;
 		} else if (matches(opt, "-color") == 0) {
-			enable_color();
+			++color;
 		} else if (matches(opt, "-help") == 0) {
 			usage();
 		} else if (matches(opt, "-netns") == 0) {
@@ -289,8 +290,8 @@ int main(int argc, char **argv)
 
 	_SL_ = oneline ? "\\" : "\n";
 
-	if (json)
-		check_if_color_enabled();
+	if (color && !json)
+		enable_color();
 
 	if (batch_file)
 		return batch(batch_file);

lib/color.c

@@ -92,14 +92,6 @@ void set_color_palette(void)
 		is_dark_bg = 1;
 }
 
-void check_if_color_enabled(void)
-{
-	if (color_is_enabled) {
-		fprintf(stderr, "Option \"-json\" conflicts with \"-color\".\n");
-		exit(1);
-	}
-}
-
 int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...)
 {
 	int ret = 0;