handle the "-s" command line option that POSIX requires

1 files changed, 6 insertions, 1 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 65babdfc1..2dd59bbb4 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4238,7 +4238,8 @@ int hush_main(int argc, char **argv)
         }
         input = stdin;
 
-        while ((opt = getopt(argc, argv, "c:xin")) > 0) {
+        /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
+        while ((opt = getopt(argc, argv, "c:xins")) > 0) {
                 switch (opt) {
                 case 'c':
                         G.global_argv = argv + optind;
@@ -4258,6 +4259,10 @@ int hush_main(int argc, char **argv)
                 case 'n':
                         G.fake_mode = 1;
                         break;
+                case 's':
+                        /* "-s" means "read from stdin", but this is how we always
+                         * operate, so simply do nothing here. */
+                        break;
                 default:
 #ifndef BB_VER
                         fprintf(stderr, "Usage: sh [FILE]...\n"