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* recommened 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 sub-class 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. In a scalar context the returned value will be a reference
to a object of the HTTP::Daemon::ClientConn class which is another
IO::Socket::INET subclass. In a list context a two-element array is
returned containing the new HTTP::Daemon::ClientConn reference and the
peer address; the list will be empty upon failure. Calling the
get_request() method on the HTTP::Daemon::ClientConn object will read
data from the client and return an HTTP::Request object reference.
This HTTP daemon does not fork(2) for you. Your application, i.e. the
user of the HTTP::Daemon is reponsible 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 HTTP::Daemon::ClientConn
class provides some methods that make this easier.
METHODS
The following is a list of methods that are new (or enhanced) relative
to the IO::Socket::INET base class.
$d = new HTTP::Daemon
The constructor takes the same parameters as the IO::Socket::INET
constructor. It can also be called without specifying any parame-
ters. 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 con-
structed like this:
$d = new HTTP::Daemon
LocalAddr => 'www.someplace.com',
LocalPort => 80;
$c = $d->accept([$pkg])
This method is the same as IO::Socket::accept but returns an
HTTP::Daemon::ClientConn reference by default. It returns undef if
you specify a timeout and no connection is made within that time.
In a scalar context the returned value will be a reference to a
object of the HTTP::Daemon::ClientConn class which is another
IO::Socket::INET subclass. In a list context a two-element array
is returned containing the new HTTP::Daemon::ClientConn reference
and the peer address; the list will be empty upon failure.
$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 HTTP::Daemon::ClientConn is also a IO::Socket::INET subclass.
Instances of this class are returned by the accept() method of
HTTP::Daemon. The following additional methods are provided:
$c->get_request([$headers_only])
Read data from the client and turn it into an HTTP::Request object
which is then returned. It returns "undef" if reading of the
request fails. If it fails, then the HTTP::Daemon::ClientConn
object ($c) should be discarded, and you should not call this
method again. The $c->reason method might give you some informa-
tion about why $c->get_request returned "undef".
The $c->get_request method supports HTTP/1.1 request content bod-
ies, including chunked transfer encoding with footer and self
delimiting multipart/* content types.
The $c->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 multi-mega-byte 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 $c->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.
$c->read_buffer([$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 returned an undefined value.
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.
$c->send_status_line( [$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.
$c->send_basic_header( [$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.
$c->send_response( [$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( $loc, [$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"
$c->send_error( [$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.
$c->send_file($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 2068
IO::Socket::INET, Apache
COPYRIGHT
Copyright 1996-2001, Gisle Aas
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
libwww-perl-5.65 2001-08-07 HTTP::Daemon(3)
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