HTTP::Lite - Lightweight HTTP implementation
use HTTP::Lite;
$http = HTTP::Lite->new;
$req = $http->request("http://www.cpan.org/";)
or die "Unable to get document: $!";
print $http->body();
Note: you should look at the HTTP::Tiny manpage or LWP
before using this module.
HTTP::Lite is a stand-alone lightweight HTTP/1.1 implementation
for perl. It is not intended as a replacement for the
fully-featured LWP module. Instead, it is intended for use in
situations where it is desirable to install the minimal number of
modules to achieve HTTP support, or where LWP is not a good
candidate due to CPU overhead, such as slower processors.
HTTP::Lite is also significantly faster than LWP.
HTTP::Lite is ideal for CGI (or mod_perl) programs or for bundling
for redistribution with larger packages where only HTTP GET and
POST functionality are necessary.
HTTP::Lite supports basic POST and GET operations only. As of
0.2.1, HTTP::Lite supports HTTP/1.1 and is compliant with the Host
header, necessary for name based virtual hosting. Additionally,
HTTP::Lite now supports Proxies.
As of 2.0.0 HTTP::Lite now supports a callback to allow processing
of request data as it arrives. This is useful for handling very
large files without consuming memory.
If you require more functionality, such as FTP or HTTPS, please
see libwwwperl (LWP). LWP is a significantly better and more
comprehensive package than HTTP::Lite, and should be used instead
of HTTP::Lite whenever possible.
- new
-
This is the constructor for HTTP::Lite. It presently takes no
arguments. A future version of HTTP::Lite might accept parameters.
- request ( $url, $data_callback, $cbargs )
-
Initiates a request to the specified URL.
Returns undef if an I/O error is encountered, otherwise the HTTP
status code will be returned. 200 series status codes represent
success, 300 represent temporary errors, 400 represent permanent
errors, and 500 represent server errors.
See http://www.w3.org/Protocols/HTTP/HTRESP.html for detailed
information about HTTP status codes.
The $data_callback parameter, if used, is a way to filter the data as it is
received or to handle large transfers. It must be a function reference, and
will be passed: a reference to the instance of the http request making the
callback, a reference to the current block of data about to be added to the
body, and the $cbargs parameter (which may be anything). It must return
either a reference to the data to add to the body of the document, or undef.
If set_callback is used, $data_callback and $cbargs are not used. $cbargs
may be either a scalar or a reference.
The data_callback is called as:
&$data_callback( $self, $dataref, $cbargs )
An example use to save a document to file is:
# Write the data to the filehandle $cbargs
sub savetofile {
my ($self,$phase,$dataref,$cbargs) = @_;
print $cbargs $$dataref;
return undef;
}
$url = "$testpath/bigbinary.dat";
open OUT, '>','bigbinary.dat';
$res = $http->request($url, \&savetofile, OUT);
close OUT;
- set_callback ( $functionref, $dataref )
-
At various stages of the request, callbacks may be used to modify the
behaviour or to monitor the status of the request. These work like the
$data_callback parameter to request(), but are more versatile. Using
set_callback disables $data_callback in
request()
The callbacks are called as:
callback ( $self, $phase, $dataref, $cbargs )
The current phases are:
connect - connection has been established and headers are being
transmitted.
content-length - return value is used as the content-length. If undef,
and prepare_post() was used, the content length is
calculated.
done-headers - all headers have been sent
content - return value is used as content and is sent to client. Return
undef to use the internal content defined by prepare_post().
content-done - content has been successfuly transmitted.
data - A block of data has been received. The data is referenced by
$dataref. The return value is dereferenced and replaces the
content passed in. Return undef to avoid using memory for large
documents.
done - Request is done.
- prepare_post ( $hashref )
-
Takes a reference to a hashed array of post form variables to upload.
Create the HTTP body and sets the method to POST.
- http11_mode ( 0 | 1 )
-
Turns on or off HTTP/1.1 support. This is off by default due to
broken HTTP/1.1 servers. Use 1 to enable HTTP/1.1 support.
- add_req_header ( $header, $value )
-
- get_req_header ( $header )
-
- delete_req_header ( $header )
-
Add, Delete, or get a HTTP
header(s) for the request. These functions
allow you to override any header. Presently, Host, User-Agent,
Content-Type, Accept, and Connection are pre-defined by the HTTP::Lite
module. You may not override Host, Connection, or Accept.
If you call add_req_header() with $value set to undef,
then the header won't be added.
To provide (proxy) authentication or authorization, you would use:
use HTTP::Lite;
use MIME::Base64;
$http = HTTP::Lite->new;
$encoded = encode_base64('username:password');
$http->add_req_header("Authorization", $encoded);
NOTE: The present implementation limits you to one instance
of each header.
- body
-
Returns the body of the document returned by the remote server.
- headers_array
-
Returns an array of the HTTP headers returned by the remote
server.
- headers_string
-
Returns a string representation of the HTTP headers returned by
the remote server.
- get_header ( $header )
-
Returns an array of values for the requested header.
NOTE: HTTP requests are not limited to a single instance of
each header. As a result, there may be more than one entry for
every header.
- protocol
-
Returns the HTTP protocol identifier, as reported by the remote
server. This will generally be either HTTP/1.0 or HTTP/1.1.
- proxy ( $proxy_server )
-
The URL or hostname of the proxy to use for the next request.
- status
-
Returns the HTTP status code returned by the server. This is
also reported as the return value of request().
- status_message
-
Returns the textual description of the status code as returned
by the server. The status string is not required to adhere to
any particular format, although most HTTP servers use a standard
set of descriptions.
- reset
-
You must call this prior to re-using an HTTP::Lite handle,
otherwise the results are undefined.
- local_addr ( $ip )
-
Explicity select the local IP address. 0.0.0.0 (default) lets the system
choose.
- local_port ( $port )
-
Explicity select the local port. 0 (default and recommended) lets the
system choose.
- method ( $method )
-
Explicity set the method. Using prepare_post or reset overrides this
setting. Usual choices are GET, POST, PUT, HEAD
# Get and print out the headers and body of the CPAN homepage
use HTTP::Lite;
$http = HTTP::Lite->new;
$req = $http->request("http://www.cpan.org/";)
or die "Unable to get document: $!";
die "Request failed ($req): ".$http->status_message()
if $req ne "200";
@headers = $http->headers_array();
$body = $http->body();
foreach $header (@headers)
{
print "$header$CRLF";
}
print "$CRLF";
print "$body$CRLF";
# POST a query to the dejanews USENET search engine
use HTTP::Lite;
$http = HTTP::Lite->new;
%vars = (
"QRY" => "perl",
"ST" => "MS",
"svcclass" => "dncurrent",
"DBS" => "2"
);
$http->prepare_post(\%vars);
$req = $http->request("http://www.deja.com/dnquery.xp";)
or die "Unable to get document: $!";
print "req: $req\n";
print $http->body();
- FTP
- HTTPS (SSL)
- Authenitcation/Authorizaton/Proxy-Authorization
are not directly supported, and require MIME::Base64.
- Redirects (Location) are not automatically followed
- multipart/form-data POSTs are not directly supported (necessary
for File uploads).
Some broken HTTP/1.1 servers send incorrect chunk sizes when transferring files.
HTTP/1.1 mode is now disabled by default.
Roy Hooper <rhooper@thetoybox.org>
Now co-maintained by Neil Bowers <neilb@cpan.org>.
This module (HTTP::Lite) is almost certainly not the best module for your needs.
For most uses the HTTP::Tiny manpage is a good choice.
If you need more features, then look at LWP.
You could also read this review of CPAN modules for making HTTP requests.
Copyright (c) 2000-2002 Roy Hooper. All rights reserved.
Some parts copyright 2009 - 2010 Adam Kennedy.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
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