Support exit status for exit/wait

One test case for returning a exit status
Passes usertests, but haven't used it to simplify tests

1 files changed, 2 insertions, 2 deletions

diff --git a/user/ln.c b/user/ln.c
index 0bb0c95..1cb96d5 100644
--- a/user/ln.c
+++ b/user/ln.c
@@ -7,9 +7,9 @@ main(int argc, char *argv[])
 {
   if(argc != 3){
     fprintf(2, "Usage: ln old new\n");
-    exit();
+    exit(-1);
   }
   if(link(argv[1], argv[2]) < 0)
     fprintf(2, "link %s %s: failed\n", argv[1], argv[2]);
-  exit();
+  exit(0);
 }