Net::HTTP - Low-level HTTP connection (client)
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;
}
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
support HTTP/1.0 and HTTP/1.1.
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):
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 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.
Host header to send. The $host
must not be set to an empty string (or undef) for HTTP/1.1.
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.
Compress::Zlib module is installed then this will
announce that this client accept both the deflate and gzip
encodings.
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.
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.
Transfer-Encoding of chunked is used.
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.
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.
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 $! as EINTR or EAGAIN (see Errno). EINTR
can happen if the application catches signals and EAGAIN can happen if
you made the socket non-blocking.
This method will raise exceptions (die) if the server does not speak proper HTTP. This can only happen when reading chunked data.
Returns the number of bytes in the read buffer. This should always be the same as:
length($s->_rbuf)
but might be more efficient.
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_.
LWP, IO::Socket::INET, Net::HTTP::NB
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.