From 2b53b3717f9d88f28fb2873b7700897360298a41 Mon Sep 17 00:00:00 2001
From: Michael Mikonos <127171689+mknos@users.noreply.github.com>
Date: Mon, 20 May 2024 16:04:59 +0800
Subject: [PATCH] ar: sanity check archive argument

* Don't attempt to open an archive file if no archive was specified (all valid usages require an archive to operate on)
* exit(1) in usage() to indicate that something went wrong (matches GNU version)
---
 bin/ar | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/bin/ar b/bin/ar
index c52341b5..90418c32 100755
--- a/bin/ar
+++ b/bin/ar
@@ -48,6 +48,10 @@ if ($opt_a || $opt_b) {
 
 # the archive filename
 my $archive = shift;
+unless (defined $archive) {
+     warn "$0: archive file required\n";
+     usage();
+}
 my $pAr = {};	    # the archive is just a hash of name => [ header, data ]
 my $pNames = [];         # a ref to an array of names in the order they appear
 
@@ -422,7 +426,7 @@ usage: ar -d [-v] archive file ...
    ar -t [-v] archive [file ...]
    ar -x [-ouv] archive [file ...]
 EOT
-  exit;
+  exit 1;
 }
 
 __END__