NAME

LWP::Protocol::Net::Curl - the power of libcurl in the palm of your hands!

VERSION

version 0.026

SYNOPSIS

#!/usr/bin/env perl;
use common::sense;

use LWP::Protocol::Net::Curl;
use WWW::Mechanize;

...

DESCRIPTION

Drop-in replacement for LWP, WWW::Mechanize and their derivatives to use Net::Curl as a backend.

Advantages:

• support ftp/ftps/http/https/sftp/scp protocols out-of-box (secure layer require libcurl to be compiled with TLS/SSL/libssh2 support)

• support SOCKS4/5 proxy out-of-box

• connection persistence and DNS cache (independent from LWP::ConnCache)

• lightning-fast HTTP compression and redirection

• lower CPU usage: this matters if you fork() multiple downloader instances

• asynchronous threading via Coro::Select (see eg/async.pl)

• at last but not least: 100% compatible with both LWP and WWW::Mechanize test suites!

LIBCURL INTERFACE

You may query which LWP protocols are implemented through Net::Curl by accessing @LWP::Protocol::Net::Curl::implements or %LWP::Protocol::Net::Curl::implements.

By default, every protocol listed in that array will be implemented via LWP::Protocol::Net::Curl. It is possible to import only specific protocols:

use LWP::Protocol::Net::Curl takeover => 0;
LWP::Protocol::implementor(https => 'LWP::Protocol::Net::Curl');

The default value of takeover option is true, resulting in exactly the same behavior as in:

use LWP::Protocol::Net::Curl takeover => 0;
LWP::Protocol::implementor($_ => 'LWP::Protocol::Net::Curl')
    for @LWP::Protocol::Net::Curl::implements;

Default curl_easy_setopt() options can be set during initialization:

use LWP::Protocol::Net::Curl
    encoding    => '',  # use HTTP compression by default
    referer     => 'http://google.com/',
    verbose     => 1;   # make libcurl print lots of stuff to STDERR

Or during runtime, using special HTTP headers (prefixed by X-CurlOpt-):

use LWP::Protocol::Net::Curl;
use LWP::UserAgent;

my $ua = LWP::UserAgent->new;
my $res = $ua->get(
    'https://metacpan.org/',
    X_CurlOpt_Verbose => 1,
);

Options set this way have the lowest precedence. For instance, if WWW::Mechanize sets the Referer: by it's own, the value you defined above won't be used.

DEBUGGING

Quickly enable libcurl verbose mode via PERL5OPT environment variable:

PERL5OPT=-MLWP::Protocol::Net::Curl=verbose,1 perl your-script.pl

Bonus: it works even if you don't include the use LWP::Protocol::Net::Curl line!

TODO

• better implementation for non-HTTP protocols

• more tests

• expose the inner guts of libcurl while handling encoding/redirects internally

• revise Net::Curl::Multi "event loop" code

BUGS

• sometimes still complains about Attempt to free unreferenced scalar: SV 0xdeadbeef during global destruction.

• in "async mode", each LWP::UserAgent instance "blocks" until all requests finish

• parallel requests via Coro::Select are very inefficient; consider using YADA if you're into event-driven parallel user agents

• Net::Curl::Share support is disabled on threaded Perl builds

SEE ALSO

• LWP::Protocol::GHTTP - used as a reference for LWP::Protocol implementation

• LWP::Protocol::AnyEvent::http - another LWP::Protocol reference

• YADA - Net::Curl usage reference

• Net::Curl - backend for this module

• LWP::Curl - provides LWP::UserAgent-compatible API via WWW::Curl

AUTHOR

Stanislaw Pusep <stas@sysd.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Stanislaw Pusep.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

CONTRIBUTORS

• José Joaquín Atria <jjatria@gmail.com>

• Nick Kostyria <kostirya@gmail.com>

• Peter Williams <pjwilliams@gmail.com>