NAME
Net::HTTP - Low-level HTTP connection (client)
VERSION
version 6.10
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);
die "read failed: $!" unless defined $n;
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. The Net::HTTP class supports
HTTP/1.0 and HTTP/1.1.
Net::HTTP is a sub-class of one of IO::Socket::IP (IPv6+IPv4),
IO::Socket::INET6 (IPv6+IPv4), or IO::Socket::INET (IPv4 only). 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 method takes the same options as
IO::Socket::INET's 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
The Host option is also the default for IO::Socket::INET's PeerAddr.
The PeerPort defaults to 80 if not provided. The PeerPort
specification can also be embedded in the PeerAddr by preceding it
with a ":", and closing the IPv6 address on brackets "[]" if
necessary: "192.0.2.1:80","[2001:db8::1]:80","any.example.com:80".
The Listen option provided by IO::Socket::INET's constructor method
is not allowed.
If unable to connect to the given HTTP server then the constructor
returns undef and $@ contains the reason. After a successful connect,
a Net:HTTP object is returned.
$s->host
Get/set the default value of the Host header to send. The $host must
not be set to an empty string (or undef) for HTTP/1.1.
$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
choose to use. The list of encodings announced as accepted by this
client depends on availability of the following modules:
Compress::Raw::Zlib for deflate, and IO::Compress::Gunzip for gzip.
$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 8192. A value of 0 means no limit.
$s->max_header_length
Get/set a limit on the number of header 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->format_chunk( $data )
Returns the string to be written for the given chunk of data.
$s->write_chunk($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_eof( %trailers )
Returns the string to be written for signaling EOF when a
Transfer-Encoding of chunked is used.
$s->write_chunk_eof( %trailers )
Will write eof marker for chunked data and optional trailers. Note
that trailers should not really be used unless is was signaled with a
Trailer header.
Returns true if successful.
($code, $mess, %headers) = $s->read_response_headers( %opts )
Read response headers from server and return it. 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
even occur multiple times, assigning these values directly to a hash
is not wise. Only the $code is returned if this method is called in
scalar context.
As a side effect this method updates the 'peer_http_version'
attribute.
Options might be passed in as key/value pairs. There are currently
only two options supported; laxed and junk_out.
The laxed option will make read_response_headers() more forgiving
towards servers that have not learned how to speak HTTP properly. The
laxed option is a boolean flag, and is enabled by passing in a TRUE
value. The junk_out option can be used to capture bad header lines
when laxed is enabled. The value should be an array reference. Bad
header lines will be pushed onto the array.
The laxed option must be specified in order to communicate with
pre-HTTP/1.0 servers that don't describe the response outcome or the
data they send back with a header block. For these servers
peer_http_version is set to "0.9" and this method returns (200,
"Assumed OK").
The method will raise an exception (die) if the server does not speak
proper HTTP or if the max_line_length or max_header_length limits are
reached. If the laxed option is turned on and max_line_length and
max_header_length checks are turned off, then no exception will be
raised and this method will always return a response code.
$n = $s->read_entity_body($buf, $size);
Reads chunks of the entity body content. Basically the same interface
as for read() and sysread(), but the buffer offset argument is not
supported yet. This method should only be called after a successful
read_response_headers() call.
The return value will be undef on read errors, 0 on EOF, -1 if no
data could be returned this time, otherwise the number of bytes
assigned to $buf. The $buf is set to "" when the return value is -1.
You normally want to retry this call if this function returns either
-1 or undef with $! as EINTR or EAGAIN (see Errno). EINTR can happen
if the application catches signals and EAGAIN can happen if you made
the socket non-blocking.
This method will raise exceptions (die) if the server does not speak
proper HTTP. This can only happen when reading chunked data.
%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.
$s->_rbuf_length
Returns the number of bytes in the read buffer. This should always be
the same as:
length($s->_rbuf)
but might be more efficient.
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 control 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
AUTHOR
Gisle Aas <gisle@activestate.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2001-2016 by Gisle Aas.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.