NAME

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

VERSION

    version 0.027

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 <http://curl.haxx.se/> 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
      <https://en.wikipedia.org/wiki/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
    <http://curl.haxx.se/libcurl/c/curl_easy_setopt.html> 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) 2025 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>

