[iproute2,2/2] color: Handle NO_COLOR environment variable in default_color_opt()

Commit Message

Ben Hutchings March 19, 2025, 9:51 p.m. UTC

The NO_COLOR environment variable is a widely supported way for users
to disable coloured text output.  See <https://no-color.org/>.  In
case iproute2 is configured to use colours by default, allow this to
be overridden by setting NO_COLOR.

This is done in default_color_opt() so that colours can still be
explicitly enabled with a command-line option.

Signed-off-by: Ben Hutchings <[e-mail]>
---
 lib/color.c | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/lib/color.c b/lib/color.c
index 5c4cc329..3c6db08d 100644
--- a/lib/color.c
+++ b/lib/color.c
@@ -83,6 +83,13 @@  static void enable_color(void)
 
 int default_color_opt(void)
 {
+	const char *no_color;
+
+	/* If NO_COLOR has a non-empty value, coloured output is never wanted */
+	no_color = getenv("NO_COLOR");
+	if (no_color && *no_color)
+		return COLOR_OPT_NEVER;
+
 	return CONF_COLOR;
 }