Net::HTTP - Low-level HTTP connection |
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
):
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
should not be set to an empty string (or undef
).
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
annouce that this client accept both the deflate and gzip
encodings.
read_response_headers()
method call.
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 $content is given (and it is non-empty), then a Content-Length
header is automatically added unless it was already present.
write_chunk($data)
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.
Trailer
header.
Returns true if successful.
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.
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 assgined
to $buf. The $buf set to ``'' when the return value is -1.
This method will raise exceptions (die) if the server does not speak proper HTTP. This can only happen when reading chunked data.
read_entity_body()
has returned 0 to indicate end of the entity
body, you might call this method to pick up any trailers.
read_response_headers()
and
read_entity_body()
methods use an internal buffer which they will look
for data before they actually sysread more from the socket itself. If
they read too much, the remaining data will be left in this buffer.
length($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 contol how reading takes place.
The object itself is a glob. Subclasses should avoid using hash key
names prefixed with http_
and io_
.
the LWP manpage, the IO::Socket::INET manpage, the Net::HTTP::NB manpage
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.
Net::HTTP - Low-level HTTP connection |