make _escape_argument() readonly-safe on older Perls

diff --git a/bindings/perl/lib/Collectd/Unixsock.pm b/bindings/perl/lib/Collectd/Unixsock.pm
index 5c6a5f9..69c755b 100644 (file)
--- a/bindings/perl/lib/Collectd/Unixsock.pm
+++ b/bindings/perl/lib/Collectd/Unixsock.pm
@@ -137,13 +137,13 @@ sub _parse_identifier
 
 sub _escape_argument
 {
-       local $_ = shift;
+    my $arg = shift;
 
-       return $_ if /^\w+$/;
+       return $arg if $arg =~ /^\w+$/;
 
-       s#\\#\\\\#g;
-       s#"#\\"#g;
-       return "\"$_\"";
+       $arg =~ s#\\#\\\\#g;
+       $arg =~ s#"#\\"#g;
+       return "\"$arg\"";
 }
 
 # Send a command on a socket, including any required argument escaping.