HTTP::Daemon
HTTP::Daemon(3) User Contributed Perl Documentation HTTP::Daemon(3)
NAME
HTTP::Daemon - a simple http server class
SYNOPSIS
use HTTP::Daemon;
use HTTP::Status;
my $d = HTTP::Daemon->new || die;
print "Please contact me at: <URL:", $d->url, ">\n";
while (my $c = $d->accept) {
while (my $r = $c->get_request) {
if ($r->method eq 'GET' and $r->url->path eq "/xyzzy") {
# remember, this is *not* recommended practice :-)
$c->send_file_response("/etc/passwd");
}
else {
$c->send_error(RC_FORBIDDEN)
}
}
$c->close;
undef($c);
}
DESCRIPTION
Instances of the "HTTP::Daemon" class are HTTP/1.1 servers that listen
on a socket for incoming requests. The "HTTP::Daemon" is a subclass of
"IO::Socket::INET", so you can perform socket operations directly on it
too.
The accept() method will return when a connection from a client is
available. The returned value will be an "HTTP::Daemon::ClientConn"
object which is another "IO::Socket::INET" subclass. Calling the
get_request() method on this object will read data from the client and
return an "HTTP::Request" object. The ClientConn object also provide
methods to send back various responses.
This HTTP daemon does not fork(2) for you. Your application, i.e. the
user of the "HTTP::Daemon" is responsible for forking if that is desir-
able. Also note that the user is responsible for generating responses
that conform to the HTTP/1.1 protocol.
The following methods of "HTTP::Daemon" are new (or enhanced) relative
to the "IO::Socket::INET" base class:
$d = HTTP::Daemon->new
$d = HTTP::Daemon->new( %opts )
The constructor method takes the same arguments as the
"IO::Socket::INET" constructor, but unlike its base class it can
also be called without any arguments. The daemon will then set up
a listen queue of 5 connections and allocate some random port num-
ber.
A server that wants to bind to some specific address on the stan-
dard HTTP port will be constructed like this:
$d = HTTP::Daemon->new(
LocalAddr => 'www.thisplace.com',
LocalPort => 80,
);
See IO::Socket::INET for a description of other arguments that can
be used configure the daemon during construction.
$c = $d->accept
$c = $d->accept( $pkg )
($c, $peer_addr) = $d->accept
This method works the same the one provided by the base class, but
it returns an "HTTP::Daemon::ClientConn" reference by default. If
a package name is provided as argument, then the returned object
will be blessed into the given class. It is probably a good idea
to make that class a subclass of "HTTP::Daemon::ClientConn".
The accept method will return "undef" if timeouts have been enabled
and no connection is made within the given time. The timeout()
method is described in IO::Socket.
In list context both the client object and the peer address will be
returned; see the description of the accept method IO::Socket for
details.
$d->url
Returns a URL string that can be used to access the server root.
$d->product_tokens
Returns the name that this server will use to identify itself.
This is the string that is sent with the "Server" response header.
The main reason to have this method is that subclasses can override
it if they want to use another product name.
The default is the string "libwww-perl-daemon/#.##" where "#.##" is
replaced with the version number of this module.
The "HTTP::Daemon::ClientConn" is a "IO::Socket::INET" subclass.
Instances of this class are returned by the accept() method of
"HTTP::Daemon". The following methods are provided:
$c->get_request
$c->get_request( $headers_only )
This method read data from the client and turns it into an
"HTTP::Request" object which is returned. It returns "undef" if
reading fails. If it fails, then the "HTTP::Daemon::ClientConn"
object ($c) should be discarded, and you should not try call this
method again on it. The $c->reason method might give you some
information about why $c->get_request failed.
The get_request() method will normally not return until the whole
request has been received from the client. This might not be what
you want if the request is an upload of a large file (and with
chunked transfer encoding HTTP can even support infinite request
messages - uploading live audio for instance). If you pass a TRUE
value as the $headers_only argument, then get_request() will return
immediately after parsing the request headers and you are responsi-
ble for reading the rest of the request content. If you are going
to call $c->get_request again on the same connection you better
read the correct number of bytes.
$c->read_buffer
$c->read_buffer( $new_value )
Bytes read by $c->get_request, but not used are placed in the read
buffer. The next time $c->get_request is called it will consume
the bytes in this buffer before reading more data from the network
connection itself. The read buffer is invalid after
$c->get_request has failed.
If you handle the reading of the request content yourself you need
to empty this buffer before you read more and you need to place
unconsumed bytes here. You also need this buffer if you implement
services like 101 Switching Protocols.
This method always return the old buffer content and can optionally
replace the buffer content if you pass it an argument.
$c->reason
When $c->get_request returns "undef" you can obtain a short string
describing why it happened by calling $c->reason.
$c->proto_ge( $proto )
Return TRUE if the client announced a protocol with version number
greater or equal to the given argument. The $proto argument can be
a string like "HTTP/1.1" or just "1.1".
$c->antique_client
Return TRUE if the client speaks the HTTP/0.9 protocol. No status
code and no headers should be returned to such a client. This
should be the same as !$c->proto_ge("HTTP/1.0").
$c->head_request
Return TRUE if the last request was a "HEAD" request. No content
body must be generated for these requests.
$c->force_last_request
Make sure that $c->get_request will not try to read more requests
off this connection. If you generate a response that is not self
delimiting, then you should signal this fact by calling this
method.
This attribute is turned on automatically if the client announces
protocol HTTP/1.0 or worse and does not include a "Connection:
Keep-Alive" header. It is also turned on automatically when
HTTP/1.1 or better clients send the "Connection: close" request
header.
$c->send_status_line
$c->send_status_line( $code )
$c->send_status_line( $code, $mess )
$c->send_status_line( $code, $mess, $proto )
Send the status line back to the client. If $code is omitted 200
is assumed. If $mess is omitted, then a message corresponding to
$code is inserted. If $proto is missing the content of the
$HTTP::Daemon::PROTO variable is used.
$c->send_crlf
Send the CRLF sequence to the client.
$c->send_basic_header
$c->send_basic_header( $code )
$c->send_basic_header( $code, $mess )
$c->send_basic_header( $code, $mess, $proto )
Send the status line and the "Date:" and "Server:" headers back to
the client. This header is assumed to be continued and does not
end with an empty CRLF line.
See the description of send_status_line() for the description of
the accepted arguments.
$c->send_response( $res )
Write a "HTTP::Response" object to the client as a response. We
try hard to make sure that the response is self delimiting so that
the connection can stay persistent for further request/response
exchanges.
The content attribute of the "HTTP::Response" object can be a nor-
mal string or a subroutine reference. If it is a subroutine, then
whatever this callback routine returns is written back to the
client as the response content. The routine will be called until
it return an undefined or empty value. If the client is HTTP/1.1
aware then we will use chunked transfer encoding for the response.
$c->send_redirect( $loc )
$c->send_redirect( $loc, $code )
$c->send_redirect( $loc, $code, $entity_body )
Send a redirect response back to the client. The location ($loc)
can be an absolute or relative URL. The $code must be one the redi-
rect status codes, and defaults to "301 Moved Permanently"
$c->send_error
$c->send_error( $code )
$c->send_error( $code, $error_message )
Send an error response back to the client. If the $code is missing
a "Bad Request" error is reported. The $error_message is a string
that is incorporated in the body of the HTML entity body.
$c->send_file_response( $filename )
Send back a response with the specified $filename as content. If
the file is a directory we try to generate an HTML index of it.
$c->send_file( $filename )
$c->send_file( $fd )
Copy the file to the client. The file can be a string (which will
be interpreted as a filename) or a reference to an "IO::Handle" or
glob.
$c->daemon
Return a reference to the corresponding "HTTP::Daemon" object.
SEE ALSO
RFC 2616
IO::Socket::INET, IO::Socket
COPYRIGHT
Copyright 1996-2003, Gisle Aas
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.8.6 2007-07-19 HTTP::Daemon(3)
