diff -r 0fde44ae8f1d -r fb6344bb32dc redisplay
--- a/redisplay	Wed Feb 12 22:54:50 2014 +0100
+++ b/redisplay	Wed Feb 12 23:05:45 2014 +0100
@@ -1,14 +1,25 @@
 #! /usr/bin/perl
 # Heiko Schlittermann
+# needs qrencode
 use 5.014;
 use warnings;
 use Sys::Hostname;
+use Pod::Usage;
+use Getopt::Long;
+
+our $VERSION = 0.1;
 
 sub url_encode {
-    shift =~ s/(?i:([^a-z]))/sprintf '%%%02x', ord $1/rge;
+    return shift =~ s/(?i:([^a-z]))/sprintf '%%%02x', ord $1/rge;
 }
 
 sub main {
+
+    GetOptions(
+        'h|help' => sub { pod2usage(-exit => 0, -verbose => 1) },
+        'm|man'  => sub { pod2usage(-exit => 0, -verbose => 2) },
+    ) or pod2usage;
+
     if (@ARGV) { splice @ARGV, 1 }
     else       { @ARGV = ("$ENV{HOME}/.google_authenticator") }
 
@@ -18,7 +29,7 @@
     my ($secret) = $google =~ /\A(\S+)/
       or die "$0: Can't read secret from $ARGV.\n";
 
-    my ($method) = map { lc } $google =~ /^"\s(.)\S+_AUTH$/m
+    my ($method) = map { lc } $google =~ /^"\s+(.)\S+_AUTH$/m
       or die "$0: Can't read method (time/hash) from $ARGV.\n";
 
     my $user = $ENV{USER} // $ENV{LOGNAME} // getpwuid $>;
@@ -27,14 +38,37 @@
     open(my $o, '>&STDOUT');
     if (-t STDIN) {
         open STDOUT, '|qrencode -t ansi256'
-          or die "$0: Can't open qrencode: $!\n";
+          or die "$0: Can't open helper binary `qrencode': $!\n";
     }
 
     printf "otpauth://%sotp/%s?secret=%s\n", $method,
       url_encode("$user\@$host"), $secret;
 
     close(STDOUT);
-
+    return 0;
 }
 
 exit main unless caller;
+
+=head1 NAME
+
+  redisplay - redisplay the google authenticator qr code
+
+=head1 SYNOPSIS
+
+  redisplay [secretfile]
+
+=head1 DESCRIPTION
+
+B<redisplay> reads the F<.google_authenticator> file, extracts
+the information an redisplays an ANSI256 QR code.
+
+The external B<qrencode> tool needs to be present in your PATH.
+
+=head1 AUTHOR
+
+Heiko Schlittermann L<hs@schlittermann.de>. The
+
+Source is at L<https://ssl.schlittermann.de/hg/google-authenticator-qr>
+
+=cut