Manpages - HTTP_Tiny.3perl
Table of Contents
NAME
:Tiny - A small, simple, correct HTTP/1.1 client
VERSION
version 0.076
SYNOPSIS
use :Tiny; my $response = :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 requests without the overhead of a large framework like LWP::UserAgent.
It is more correct and more complete than :Lite. It supports proxies and redirection. It also correctly resumes after EINTR.
If IO::Socket::IP 0.25 or later is installed, :Tiny will use it instead of IO::Socket::INET for transparent support for both IPv4 and IPv6.
Cookie support requires :CookieJar or an equivalent class.
METHODS
new
$http = :Tiny->new( %attributes );
This constructor returns a new :Tiny object. Valid attributes include:
agent
X A user-agent string (defaults to ’HTTP-Tiny/$VERSION’). Ifagent
X ends in a space character, the default user-agent string is appended.cookie_jar
X An instance of :CookieJar X or equivalent class that supports theadd
andcookie_header
methodsdefault_headers
X A hashref of default headers to apply to requestslocal_address
X The local IP address to bind tokeep_alive
X Whether to reuse the last connection (if for the same scheme, host and port) (defaults to 1)max_redirect
X Maximum number of redirects allowed (defaults to 5)max_size
X Maximum response size in bytes (only when not using a data callback). If defined, responses larger than this will return an exception.http_proxy
X URL of a proxy server to use for HTTP connections (default is$ENV{http_proxy}
X if set)https_proxy
X URL of a proxy server to use for HTTPS connections (default is$ENV{https_proxy}
X if set)proxy
X URL of a generic proxy server for both HTTP and HTTPS connections (default is$ENV{all_proxy}
X if set)no_proxy
X List of domain suffixes that should not be proxied. Must be a comma-separated string or an array reference. (default is$ENV{no_proxy}
X)timeout
X Request timeout in seconds (default is 60) If a socket open, read or write takes longer than the timeout, an exception is thrown.verify_SSL
X A boolean that indicates whether to validate the SSL certificate of anhttps
X connection (default is false)SSL_options
X A hashref ofSSL_*
X options to pass through to IO::Socket::SSL
Passing an explicit undef
for proxy
, http_proxy
or https_proxy
will prevent getting the corresponding proxies from the environment.
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.
The keep_alive
parameter enables a persistent connection, but only to
a single destination scheme, host and port. Also, if any
connection-relevant attributes are modified, or if the process ID or
thread ID change, the persistent connection will be dropped. If you want
persistent connections across multiple destinations, use multiple
:Tiny objects.
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
. If data is
provided as an array reference, the order is preserved; if provided as a
hash reference, the terms are sorted on key and value for consistency.
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 include 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.
NOTE: Method names are case-sensitive per the HTTP/1.1
specification. Don’t use get
when you really want GET
. See
LIMITATIONS for how this applies to redirection.
If the URL includes a user:password stanza, they will be used for Basic-style authorization headers. (Authorization headers will not be included in a redirected request.) For example:
$http->request(GET, http://aladdin:open sesame@example.com/);
If the user:password stanza contains reserved characters, they must be percent-escaped:
$http->request(GET, http://john%2540example.com:password@example.com/);
A hashref of options may be appended to modify the request.
Valid options are:
headers
X 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
X 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 requesttrailer_callback
X 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
X A code reference that will be called for each chunks of the response body received.peer
X Override host resolution and force all connections to go only to a specific peer address, regardless of the URL of the request. This will include any redirections! This options should be used with extreme caution (e.g. debugging or very special circumstances). It can be given as either a scalar or a code reference that will receive the hostname and whose response will be taken as the address.
The Host
header is generated from the URL in accordance with RFC 2616.
It is a fatal error to specify Host
in the headers
option. Other
headers may be ignored or overwritten if necessary for transport
compliance.
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 content
option is the empty string, no content-type
or
content-length
headers will be generated.
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
X Boolean indicating whether the operation returned a 2XX status codeurl
X 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 chainstatus
X The HTTP status code of the responsereason
X The response phrase returned by the servercontent
X 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 stringheaders
X 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 valueprotocol
- If this field exists, it is the protocol of the response such as HTTP/1.0 or HTTP/1.1redirects
If this field exists, it is an arrayref of response hash references from redirects in the same order that redirections occurred. If it does not exist, then no redirections occurred.
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. If data is provided as a hash
reference, the key/value pairs in the resulting string will be sorted by
key and value for consistent ordering.
can_ssl
$ok = :Tiny->can_ssl; ($ok, $why) = :Tiny->can_ssl; ($ok, $why) = $http->can_ssl;
Indicates if SSL support is available. When called as a class object, it
checks for the correct version of Net::SSLeay and IO::Socket::SSL. When
called as an object methods, if SSL_verify
is true or if
SSL_verify_mode
is set in SSL_options
, it checks that a CA file is
available.
In scalar context, returns a boolean indicating if SSL is available. In list context, returns the boolean and a (possibly multi-line) string of errors indicating why SSL isn’t available.
connected
$host = $http->connected; ($host, $port) = $http->connected;
Indicates if a connection to a peer is being kept alive, per the
keep_alive
option.
In scalar context, returns the peer host and port, joined with a colon,
or undef
(if no peer is connected). In list context, returns the peer
host and port or an empty list (if no peer is connected).
Note: This method cannot reliably be used to discover whether the remote host has closed its end of the socket.
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 new enough versions of these modules are not installed or
if the SSL encryption fails. You can also use HTTP::Tiny::can_ssl()
utility function that returns boolean to see if the required modules are
installed.
An https
connection may be made via an http
proxy that supports the
CONNECT command (i.e. RFC 2817). You may not proxy https
via a proxy
that itself requires https
to communicate.
SSL provides two distinct capabilities:
- Encrypted communication channel
- Verification of server identity
By default, :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, :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 :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 environment variable SSL_CERT_FILE
is present, :Tiny will
try to find a CA certificate file in that location.
If the Mozilla::CA module is installed, :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 :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
: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.
PROXY SUPPORT
:Tiny can proxy both http
and https
requests. Only Basic proxy
authorization is supported and it must be provided as part of the proxy
URL: http://user:pass@proxy.example.com/
.
:Tiny supports the following proxy environment variables:
- http_proxy or HTTP_PROXY
- https_proxy or HTTPS_PROXY
- all_proxy or ALL_PROXY
If the REQUEST_METHOD
environment variable is set, then this might be
a CGI process and HTTP_PROXY
would be set from the Proxy:
header,
which is a security risk. If REQUEST_METHOD
is set, HTTP_PROXY
(the
upper case variant only) is ignored.
Tunnelling https
over an http
proxy using the CONNECT method is
supported. If your proxy uses https
itself, you can not tunnel https
over it.
Be warned that proxying an https
connection opens you to the risk of a
man-in-the-middle attack by the proxy server.
The no_proxy
environment variable is supported in the format of a
comma-separated list of domain extensions proxy should not be used for.
Proxy arguments passed to new
will override their corresponding
environment variables.
LIMITATIONS
:Tiny is conditionally compliant with the HTTP/1.1 specifications http://www.w3.org/Protocols/:
- Message Syntax and Routing [RFC7230]
- Semantics and Content [RFC7231]
- Conditional Requests [RFC7232]
- Range Requests [RFC7233]
- Caching [RFC7234]
- Authentication [RFC7235]
It attempts to meet all MUST requirements of the specification, but does not implement all SHOULD requirements. (Note: it was developed against the earlier RFC 2616 specification and may not yet meet the revised RFC 7230-7235 spec.)
Some particular limitations of note include:
- :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, 307 and 308 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.
- There is no provision for delaying a request body using an
Expect
header. Unexpected1XX
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.
- Headers mentioned in the RFCs and some other, well-known headers are generated with their canonical case. Other headers are sent in the case provided by the user. Except for control headers (which are sent first), headers are sent in arbitrary order.
Despite the limitations listed above, :Tiny is considered feature-complete. New feature requests should be directed to :Tiny::UA.
SEE ALSO
- :Tiny::UA - Higher level UA features for :Tiny
- :Thin - :Tiny wrapper with :Request/HTTP::Response compatibility
- :Tiny::Mech - Wrap WWW::Mechanize instance in :Tiny compatible interface
- IO::Socket::IP - Required for IPv6 support
- IO::Socket::SSL - Required for SSL support
- LWP::UserAgent - If :Tiny isn’t enough for you, this is the standard way to do things
- Mozilla::CA - Required if you want to validate SSL certificates
- Net::SSLeay - Required for SSL support
SUPPORT
Bugs / Feature Requests
Please report any bugs or feature requests through the issue tracker at https://github.com/chansen/p5-http-tiny/issues. 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.
AUTHORS
- Christian Hansen <chansen@cpan.org>
- David Golden <dagolden@cpan.org>
CONTRIBUTORS
- Alan Gardner <gardner@pythian.com>
- Alessandro Ghedini <al3xbio@gmail.com>
- A. Sinan Unur <nanis@cpan.org>
- Brad Gilbert <bgills@cpan.org>
- brian m. carlson <sandals@crustytoothpaste.net>
- Chris Nehren <apeiron@cpan.org>
- Chris Weyl <cweyl@alumni.drew.edu>
- Claes Jakobsson <claes@surfar.nu>
- Clinton Gormley <clint@traveljury.com>
- Craig A. Berry <craigberry@mac.com>
- Craig Berry <cberry@cpan.org>
- David Golden <xdg@xdg.me>
- David Mitchell <davem@iabyn.com>
- Dean Pearce <pearce@pythian.com>
- Edward Zborowski <ed@rubensteintech.com>
- Felipe Gasper <felipe@felipegasper.com>
- James Raspass <jraspass@gmail.com>
- Jeremy Mates <jmates@cpan.org>
- Jess Robinson <castaway@desert-island.me.uk>
- Karen Etheridge <ether@cpan.org>
- Lukas Eklund <leklund@gmail.com>
- Martin J. Evans <mjegh@ntlworld.com>
- Martin-Louis Bright <mlbright@gmail.com>
- Mike Doherty <doherty@cpan.org>
- Nicolas Rochelemagne <rochelemagne@cpanel.net>
- Olaf Alders <olaf@wundersolutions.com>
- Olivier Mengue <dolmen@cpan.org>
- Petr PisaX <ppisar@redhat.com>
- Serguei Trouchelle <stro@cpan.org>
- Shoichi Kaji <skaji@cpan.org>
- SkyMarshal <skymarshal1729@gmail.com>
- So\k:.ren Kornetzki <soeren.kornetzki@delti.com>
- Steve Grazzini <steve.grazzini@grantstreet.com>
- Syohei YOSHIDA <syohex@gmail.com>
- Tatsuhiko Miyagawa <miyagawa@bulknews.net>
- Tom Hukins <tom@eborcom.com>
- Tony Cook <tony@develop-help.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2018 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.