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Net::HTTP(3pm) - phpMan
Net::HTTP(3pm) User Contributed Perl Documentation Net::HTTP(3pm)
NAME
Net::HTTP - Low-level HTTP connection (client)
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
bracktes "[]" 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
COPYRIGHT
Copyright 2001-2003 Gisle Aas.
This library is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.
perl v5.18.2 2014-07-24 Net::HTTP(3pm)
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