HTTP::Tiny(3)

NAME
HTTP::Tiny - A small, simple, correct HTTP/1.1 client

VERSION
version 0.025

SYNOPSIS
    use HTTP::Tiny;

    my $response = HTTP::Tiny->new->get('http://example.com/');

    die "Failed!\n" unless $response->{success};

    print "$response->{status} $response->{reason}\n";

    while (my ($k, $v) = each %{$response->{headers}}) {
        for (ref $v eq 'ARRAY' ? @$v : $v) {
            print "$k: $_\n";
        }
    }

    print $response->{content} if length $response->{content};

DESCRIPTION
This is a very simple HTTP/1.1 client, designed for doing simple GET requests without the overhead of a large framework like LWP::UserAgent.

It is more correct and more complete than HTTP::Lite. It supports proxies (currently only non-authenticating ones) and redirection. It also correctly resumes after EINTR.

METHODS

  new
    $http = HTTP::Tiny->new( %attributes );

This constructor returns a new HTTP::Tiny object. Valid attributes include:

•   "agent"

    A user-agent string (defaults to 'HTTP-Tiny/$VERSION'). If "agent" ends in a space character, the default user-agent string is appended.

•   "default_headers"

    A hashref of default headers to apply to requests

•   "local_address"

    The local IP address to bind to

•   "max_redirect"

    Maximum number of redirects allowed (defaults to 5)

•   "max_size"

    Maximum response size (only when not using a data callback). If defined, responses larger than this will return an exception.

•   "proxy"

    URL of a proxy server to use (default is $ENV{http_proxy} if set)

•   "timeout"

    Request timeout in seconds (default is 60)

•   "verify_SSL"

    A boolean that indicates whether to validate the SSL certificate of an "https" connection (default is false)

•   "SSL_options"

    A hashref of "SSL_*" options to pass through to IO::Socket::SSL

Exceptions from "max_size", "timeout" or other errors will result in a pseudo-HTTP status code of 599 and a reason of "Internal Exception". The content field in the response will contain the text of the exception.

See "SSL SUPPORT" for more on the "verify_SSL" and "SSL_options" attributes.

  get|head|put|post|delete
    $response = $http->get($url);
    $response = $http->get($url, \%options);
    $response = $http->head($url);

These methods are shorthand for calling "request()" for the given method. The URL must have unsafe characters escaped and international domain names encoded. See "request()" for valid options and a description of the response.

The "success" field of the response will be true if the status code is 2XX.

  post_form
    $response = $http->post_form($url, $form_data);
    $response = $http->post_form($url, $form_data, \%options);

This method executes a "POST" request and sends the key/value pairs from a form data hash or array reference to the given URL with a "content-type" of "application/x-www-form-urlencoded". See documentation for the "www_form_urlencode" method for details on the encoding.

The URL must have unsafe characters escaped and international domain names encoded. See "request()" for valid options and a description of the response. Any "content-type" header or content in the options hashref will be ignored.

The "success" field of the response will be true if the status code is 2XX.

  mirror
    $response = $http->mirror($url, $file, \%options)
    if ( $response->{success} ) {
        print "$file is up to date\n";
    }

Executes a "GET" request for the URL and saves the response body to the file name provided. The URL must have unsafe characters escaped and international domain names encoded. If the file already exists, the request will includes an "If-Modified-Since" header with the modification timestamp of the file. You may specify a different "If-Modified-Since" header yourself in the "$options->{headers}" hash.

The "success" field of the response will be true if the status code is 2XX or if the status code is 304 (unmodified).

If the file was modified and the server response includes a properly formatted "Last-Modified" header, the file modification time will be updated accordingly.

  request
    $response = $http->request($method, $url);
    $response = $http->request($method, $url, \%options);

Executes an HTTP request of the given method type ('GET', 'HEAD', 'POST', 'PUT', etc.) on the given URL. The URL must have unsafe characters escaped and international domain names encoded. A hashref of options may be appended to modify the request.

Valid options are:

•   "headers"

    A hashref containing headers to include with the request. If the value for a header is an array reference, the header will be output multiple times with each value in the array. These headers over-write any default headers.

•   "content"

    A scalar to include as the body of the request OR a code reference that will be called iteratively to produce the body of the request

•   "trailer_callback"

    A code reference that will be called if it exists to provide a hashref of trailing headers (only used with chunked transfer-encoding)

•   "data_callback"

    A code reference that will be called for each chunks of the response body received.

If the "content" option is a code reference, it will be called iteratively to provide the content body of the request. It should return the empty string or undef when the iterator is exhausted.

If the "data_callback" option is provided, it will be called iteratively until the entire response body is received. The first argument will be a string containing a chunk of the response body, the second argument will be the in-progress response hash reference, as described below. (This allows customizing the action of the callback based on the "status" or "headers" received prior to the content body.)

The "request" method returns a hashref containing the response. The hashref will have the following keys:

•   "success"

    Boolean indicating whether the operation returned a 2XX status code

•   "url"

    URL that provided the response. This is the URL of the request unless there were redirections, in which case it is the last URL queried in a redirection chain

•   "status"

    The HTTP status code of the response

•   "reason"

    The response phrase returned by the server

•   "content"

    The body of the response. If the response does not have any content or if a data callback is provided to consume the response body, this will be the empty string

•   "headers"

    A hashref of header fields. All header field names will be normalized to be lower case. If a header is repeated, the value will be an arrayref; it will otherwise be a scalar string containing the value

On an exception during the execution of the request, the "status" field will contain 599, and the "content" field will contain the text of the exception.

  www_form_urlencode
    $params = $http->www_form_urlencode( $data );
    $response = $http->get("http://example.com/query?$params");

This method converts the key/value pairs from a data hash or array reference into a "x-www-form-urlencoded" string. The keys and values from the data reference will be UTF-8 encoded and escaped per RFC 3986. If a value is an array reference, the key will be repeated with each of the values of the array reference. The key/value pairs in the resulting string will be sorted by key and value.

SSL SUPPORT
Direct "https" connections are supported only if IO::Socket::SSL 1.56 or greater and Net::SSLeay 1.49 or greater are installed. An exception will be thrown if a new enough versions of these modules not installed or if the SSL encryption fails. There is no support for "https" connections via proxy (i.e. RFC 2817).

SSL provides two distinct capabilities:

•   Encrypted communication channel

•   Verification of server identity

By default, HTTP::Tiny does not verify server identity.

Server identity verification is controversial and potentially tricky because it depends on a (usually paid) third-party Certificate Authority (CA) trust model to validate a certificate as legitimate. This discriminates against servers with self-signed certificates or certificates signed by free, community-driven CA's such as CAcert.org <http://cacert.org>.

By default, HTTP::Tiny does not make any assumptions about your trust model, threat level or risk tolerance. It just aims to give you an encrypted channel when you need one.

Setting the "verify_SSL" attribute to a true value will make HTTP::Tiny verify that an SSL connection has a valid SSL certificate corresponding to the host name of the connection and that the SSL certificate has been verified by a CA. Assuming you trust the CA, this will protect against a man-in-the-middle attack <http://en.wikipedia.org/wiki/Man-in-the-middle_attack>. If you are concerned about security, you should enable this option.

Certificate verification requires a file containing trusted CA certificates. If the Mozilla::CA module is installed, HTTP::Tiny will use the CA file included with it as a source of trusted CA's. (This means you trust Mozilla, the author of Mozilla::CA, the CPAN mirror where you got Mozilla::CA, the toolchain used to install it, and your operating system security, right?)

If that module is not available, then HTTP::Tiny will search several system-specific default locations for a CA certificate file:

•   /etc/ssl/certs/ca-certificates.crt

•   /etc/pki/tls/certs/ca-bundle.crt

•   /etc/ssl/ca-bundle.pem

An exception will be raised if "verify_SSL" is true and no CA certificate file is available.

If you desire complete control over SSL connections, the "SSL_options" attribute lets you provide a hash reference that will be passed through to "IO::Socket::SSL::start_SSL()", overriding any options set by HTTP::Tiny. For example, to provide your own trusted CA file:

    SSL_options => {
        SSL_ca_file => $file_path,
    }

The "SSL_options" attribute could also be used for such things as providing a client certificate for authentication to a server or controlling the choice of cipher used for the SSL connection. See IO::Socket::SSL documentation for details.

LIMITATIONS
HTTP::Tiny is conditionally compliant with the HTTP/1.1 specification <http://www.w3.org/Protocols/rfc2616/rfc2616.html>. It attempts to meet all "MUST" requirements of the specification, but does not implement all "SHOULD" requirements.

Some particular limitations of note include:

•   HTTP::Tiny focuses on correct transport. Users are responsible for ensuring that user-defined headers and content are compliant with the HTTP/1.1 specification.

•   Users must ensure that URLs are properly escaped for unsafe characters and that international domain names are properly encoded to ASCII. See URI::Escape, URI::_punycode and Net::IDN::Encode.

•   Redirection is very strict against the specification. Redirection is only automatic for response codes 301, 302 and 307 if the request method is 'GET' or 'HEAD'. Response code 303 is always converted into a 'GET' redirection, as mandated by the specification. There is no automatic support for status 305 ("Use proxy") redirections.

•   Persistent connections are not supported. The "Connection" header will always be set to "close".

•   Cookies are not directly supported. Users that set a "Cookie" header should also set "max_redirect" to zero to ensure cookies are not inappropriately re-transmitted.

•   Only the "http_proxy" environment variable is supported in the format "http://HOST:PORT/". If a "proxy" argument is passed to "new" (including undef), then the "http_proxy" environment variable is ignored.

•   There is no provision for delaying a request body using an "Expect" header. Unexpected "1XX" responses are silently ignored as per the specification.

•   Only 'chunked' "Transfer-Encoding" is supported.

•   There is no support for a Request-URI of '*' for the 'OPTIONS' request.

•   There is no support for IPv6 of any kind.

SEE ALSO

•   LWP::UserAgent

•   IO::Socket::SSL

•   Mozilla::CA

•   Net::SSLeay

SUPPORT

  Bugs / Feature Requests
Please report any bugs or feature requests through the issue tracker at <https://rt.cpan.org/Public/Dist/Display.html?Name=HTTP-Tiny>. You will be notified automatically of any progress on your issue.

  Source Code
This is open source software. The code repository is available for public review and contribution under the terms of the license.

<https://github.com/dagolden/http-tiny>

  git clone git://github.com/dagolden/http-tiny.git

AUTHORS

•   Christian Hansen <chansen@cpan.org>

•   David Golden <dagolden@cpan.org>

•   Mike Doherty <doherty@cpan.org>

COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Christian Hansen.

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