fix: better error messages

1 files changed, 7 insertions, 1 deletions

diff --git a/pm-suspend.c b/pm-suspend.c
index 5ff5abe..cb382c5 100644
--- a/pm-suspend.c
+++ b/pm-suspend.c
@@ -4,8 +4,14 @@
 int main(int argc, char **argv) {
   FILE *f = fopen("/sys/power/state", "w");
 
+  if(argc != 2) {
+	fprintf(stderr, "%s [mem|standby|freeze|disk]\n", argv[0]);
+	exit(1);
+  }
+
+
   if(f == NULL) {
-	printf("%s is unable to write to /sys/power/state.\nAdd the setuid bit?\n", argv[0]);
+	fprintf(stderr, "%s is unable to write to /sys/power/state.\nAdd the setuid bit?\n", argv[0]);
 	exit(1);
   }