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->uri->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( $headers_only )
- This method reads data from the client and turns it into an
"HTTP::Request" object which is returned. It returns
"undef" if reading fails. If it fails, then the
"HTTP::Daemon::ClientConn" object ($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 returns 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_header( $field, $value )
- $c->send_header( $field1, $value1, $field2, $value2, ... )
- Send one or more header lines.
- $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.