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

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

diff --git a/coreutils/test.c b/coreutils/test.c
index 6524c4f0733c43d90489e125c9e9b515de63eed6..8248a1ef52fdf4e0f6416369d2d50ddd313ce441 100644 (file)
--- 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;
        }