test: add examples when "%s: unknown operand" happens

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/coreutils/test.c b/coreutils/test.c
index 6524c4f07..8248a1ef5 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -878,7 +878,10 @@ int test_main(int argc, char **argv)
         res = !oexpr(check_operator(*args));
 
         if (*args != NULL && *++args != NULL) {
-                /* TODO: example when this happens? */
+                /* Examples:
+                 * test 3 -lt 5 6
+                 * test -t 1 2
+                 */
                 bb_error_msg("%s: unknown operand", *args);
                 res = 2;
         }