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 desirable. 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 number.
A server that wants to bind to some specific address on the standard 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 responsible 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->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 normal 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 redirect 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 v5.8.8 2004-12-11 HTTP::Daemon(3)
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