1 files changed, 9 insertions, 4 deletions
diff --git a/runfd.c b/runfd.c
index 3a3260e..50eea7f 100644
--- a/runfd.c
+++ b/runfd.c
@@ -10,18 +10,22 @@
  * NOTE: requires fdescfs to be mounted to run interpreted files (starting with #!)
  */
 
+#define DEFAULT_FD 3
+
 char *args[] = { "batchrun", NULL };
 
 int
 main(int argc, char **argv)
 {
-	char buf[2];
+	char buf[2], *end = NULL;
 	ssize_t ret;
-	int tries = 0;
-	int fd = 3;
+	int tries = 0, fd = DEFAULT_FD;
 
 	if (argc > 1) {
-		fd = atoi(argv[1]);
+		fd = strtol(argv[1], &end, 10);
+
+		if (end == argv[1])
+			errx(1, "Filedescriptor supplied (\"%s\") is not a number", argv[1]);
 	}
 
 retry:
@@ -36,6 +40,7 @@ retry:
 	} else if (ret == -1) {
 		if (errno == EINTR)
 			goto retry;
+		err(1, "pread()");
 	} else if (ret != 0) {
 		goto retry;
 	}