From 5bd01740ee26507e173224f341cdfe85eba82d53 Mon Sep 17 00:00:00 2001
From: Pedro Melo <melo@simplicidade.org>
Date: Mon, 21 Jul 2014 05:10:39 +0100
Subject: [PATCH] Improve consumer.pl:

* use Getopt::Long to enable/disable help, verbose and print mode;
* add proper usage message;
* keep track of total messages received.

Signed-off-by: Pedro Melo <melo@simplicidade.org>
---
 examples/consumer.pl | 43 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/examples/consumer.pl b/examples/consumer.pl
index 999f2e9..cfee71e 100755
--- a/examples/consumer.pl
+++ b/examples/consumer.pl
@@ -6,24 +6,53 @@ use FindBin;
 use lib "$FindBin::Bin/../lib";
 use AnyEvent;
 use AnyEvent::NSQ::Reader;
+use Getopt::Long;
 
-my ($topic, $channel) = @ARGV;
-die "Usage: consumer.pl topic channel\n" unless $topic and $channel;
+my ($topic, $channel, $help, $verbose, $print);
+GetOptions('help' => \$help, 'verbose' => \$verbose, 'print' => \$print) or usage();
+usage() if $help;
+
+($topic, $channel) = @ARGV;
+usage("topic and channel are required parameters") unless $topic and $channel;
 
 my $cv = AE::cv;
 
-my $c = 1;
+## return undef => mark_as_done_msg()
+my $message_cb = $print ? sub { print "$_[1]{message}\n"; return } : sub {return};
+
+my $t = 0;
 my $r = AnyEvent::NSQ::Reader->new(
   topic              => $topic,
   channel            => $channel,
   nsqd_tcp_addresses => '127.0.0.1',
   client_id          => "${channel}_consumer/pid_$$",
 
-#  message_cb => sub { print STDERR "$c: $_[1]{message}\n"; $c++; return },    ## return undef => mark_as_done_msg()
-  message_cb => sub {return},                                                 ## return undef => mark_as_done_msg()
+  message_cb => sub { $t++; $message_cb->(@_, $t) },
 
-  error_cb      => sub { warn "$_[1]\n" },
-  disconnect_cb => sub { warn "Got disconnected... exiting...\n"; $cv->send },
+  error_cb      => sub { warn "$_[1]\n" if $verbose },
+  disconnect_cb => sub { warn "Got disconnected after $t total messages... exiting...\n" if $verbose; $cv->send },
 );
 
 $cv->recv;
+
+
+sub usage {
+  print "Error: @_\n" if @_;
+
+  print <<"  EOU";
+Usage: consumer.pl [--help|-h] [--print|-p] topic channel
+
+  Consume messages from channel <channel> linked to topic <topic>.
+  Topic and channel parameters are mandatory.
+
+  Options:
+
+  --help or -h     Prints this message and exits
+  --verbose or -v  Writes debug information about connections,
+                   disconnections and errors
+
+  --print or -p    Prints each received message
+  EOU
+
+  exit(1);
+}