ls: support NO_COLOR environment variable

If the NO_COLOR environment variable is set and is not empty 'ls'
won't output ANSI colour codes.  This is an alternative to the
existing approach of setting 'LS_COLORS=none'.

See https://no-color.org/.

Costs 24-32 bytes.

(GitHub issue #382)

1 files changed, 5 insertions, 0 deletions

diff --git a/coreutils/ls.c b/coreutils/ls.c
index df4277fbd..52c43c731 100644
--- a/coreutils/ls.c
+++ b/coreutils/ls.c
@@ -1222,6 +1222,11 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
         /* set G_show_color = 1/0 */
         if (ENABLE_FEATURE_LS_COLOR_IS_DEFAULT && !is_TERM_dumb()) {
                 char *p = getenv("LS_COLORS");
+# if ENABLE_PLATFORM_MINGW32
+                /* No colour if unset or empty: https://no-color.org */
+                char *no_c = getenv("NO_COLOR");
+                if (!no_c || no_c[0] == '\0')
+# endif
                 /* LS_COLORS is unset, or (not empty && not "none") ? */
                 if (!p || (p[0] && strcmp(p, "none") != 0)) {
                         if (isatty(STDOUT_FILENO)) {