NAME

Net::HTTP - Low-level HTTP client connection

NOTE

This module is experimental. Details of its interface is likely to change in the future.

SYNOPSIS

use Net::HTTP;
my $s = Net::HTTP->new(Host => "www.perl.com) || die $@;
$s->write_request(GET => "/", 'User-Agent' => "Mozilla/5.0");
my($code, $mess, %h) = $s->read_response_headers;

while (1) {
   my $buf;
   my $n = $s->read_entity_body($buf, 1024);
   last unless $n;
   print $buf;
}

DESCRIPTION

The Net::HTTP class is a low-level HTTP client. An instance of the Net::HTTP class represents a connection to an HTTP server. The HTTP protocol is described in RFC 2616.

Net::HTTP is a sub-class of IO::Socket::INET. You can mix the methods described below with reading and writing from the socket directly. This is not necessary a good idea, unless you know what you are doing.

The following methods are provided (in addition to those of IO::Socket::INET):

$s = Net::HTTP->new( %options )

The Net::HTTP constructor takes the same options as IO::Socket::INET as well as these:

Host:            Initial host attribute value
KeepAlive:       Initial keep_alive attribute value
SendTE:          Initial send_te attribute_value
HTTPVersion:     Initial http_version attribute value
PeerHTTPVersion: Initial peer_http_version attribute value
MaxLineLength:   Initial max_line_length attribute value
MaxHeaderLines:  Initial max_header_lines attribute value

$s->host

Get/set the default value of the Host header to send. The $host should not be set to an empty string (or undef).

$s->keep_alive

Get/set the keep-alive value. If this value is TRUE then the request will be sent with headers indicating that the server should try to keep the connection open so that multiple requests can be sent.

The actual headers set will depend on the value of the http_version and peer_http_version attributes.

$s->send_te

Get/set the a value indicating if the request will be sent with a "TE" header to indicate the transfer encodings that the server can chose to use. If the Compress::Zlib module is installed then this will annouce that this client accept both the deflate and gzip encodings.

$s->http_version

Get/set the HTTP version number that this client should announce. This value can only be set to "1.0" or "1.1". The default is "1.1".

$s->peer_http_version

Get/set the protocol version number of our peer. This value will initially be "1.0", but will be updated by a successful read_response_headers() method call.

$s->max_line_length

Get/set a limit on the length of response line and response header lines. The default is 4096. A value of 0 means no limit.

$s->max_header_length

Get/set a limit on the number of headers lines that a response can have. The default is 128. A value of 0 means no limit.

$s->format_request($method, $uri, %headers, [$content])

Format a request message and return it as a string. If the headers do not include a Host header, then a header is inserted with the value of the host attribute. Headers like Connection and Keep-Alive might also be added depending on the status of the keep_alive attribute.

If $content is given (and it is non-empty), then a Content-Length header is automatically added unless it was already present.

$s->write_request($method, $uri, %headers, [$content])

Format and send a request message. Arguments are the same as for format_request(). Returns true if successful.

$s->write_chunk($data)

Will write a new chunk of request entity body data. This method should only be used if the Transfer-Encoding header with a value of chunked was sent in the request. Note, writing zero-length data is a no-op. Use the write_chunk_eof() method to signal end of entity body data.

Returns true if successful.

$s->format_chunk($data)

Returns the string to be written for the given chunk of data.

$s->write_chunk_eof(%trailers)

Will write eof marker for chunked data and optional trailers. Note that trailers should not really be used unless is was signaled with a Trailer header.

Returns true if successful.

$s->format_chunk_eof(%trailers)

Returns the string to be written for signaling EOF.

($code, $mess, %headers) = $s->read_response_headers

Read response headers from server. The $code is the 3 digit HTTP status code (see HTTP::Status) and $mess is the textual message that came with it. Headers are then returned as key/value pairs. Since key letter casing is not normalized and the same key can occur multiple times, assigning these values directly to a hash might be risky.

As a side effect this method updates the 'peer_http_version' attribute.

The method will raise exceptions (die) if the server does not speak proper HTTP.

$n = $s->read_entity_body($buf, $size);

Reads chunks of the entity body content. Basically the same interface as for read() and sysread(), but buffer offset is not supported yet. This method should only be called after a successful read_response_headers() call.

The return value will be undef on errors, 0 on EOF, -1 if no data could be returned this time, and otherwise the number of bytes added to $buf.

This method might raise exceptions (die) if the server does not speak proper HTTP.

%headers = $s->get_trailers

After read_entity_body() has returned 0 to indicate end of the entity body, you might call this method to pick up any trailers.

$s->_rbuf

Get/set the read buffer content. The read_response_headers() and read_entity_body() methods use an internal buffer which they will look for data before they actually sysread more from the socket itself. If they read too much, the remaining data will be left in this buffer.

$s->_rbuf_length

Returns the number of bytes in the read buffer.

SUBCLASSING

The read_response_headers() and read_entity_body() will invoke the sysread() method when they need more data. Subclasses might want to override this method to contol how reading takes place.

The object itself is a glob. Subclasses should avoid using hash key names prefixed with http_ and io_.

SEE ALSO

LWP, IO::Socket::INET, Net::HTTP::NB

COPYRIGHT

Copyright 2001 Gisle Aas.

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