Linux Certif

Toute la documentation sur la certification Linux LPI

Net::TCP.3pm

NAME

Net::TCP - TCP sockets interface module

SYNOPSIS

     use Net::Gen;               # optional
     use Net::Inet;              # optional
     use Net::TCP;
 
 

DESCRIPTION

The "Net::TCP" module provides services for TCP communications over sockets. It is layered atop the "Net::Inet" and "Net::Gen" modules, which are part of the same distribution.

Public Methods

The following methods are provided by the "Net::TCP" module itself, rather than just being inherited from "Net::Inet" or "Net::Gen".

new

Usage:

     $obj = new Net::TCP;
     $obj = new Net::TCP $host, $service;
     $obj = new Net::TCP \%parameters;
     $obj = new Net::TCP $host, $service, \%parameters;
     $obj = 'Net::TCP'->new();
     $obj = 'Net::TCP'->new($host, $service);
     $obj = 'Net::TCP'->new(\%parameters);
     $obj = 'Net::TCP'->new($host, $service, \%parameters);
 
 

Returns a newly-initialised object of the given class. If called for a derived class, no validation of the supplied parameters will be performed. (This is so that the derived class can add the parameter validation it needs to the object before allowing the validation.) Otherwise, it will cause the parameters to be validated by calling its "init" method, which "Net::TCP" inherits from "Net::Inet". In particular, this means that if both a host and a service are given, then an object will only be returned if a connect() call was successful (or is still in progress, if the object is non-blocking).

The examples above show the indirect object syntax which many prefer, as well as the guaranteed-to-be-safe static method call. There are occasional problems with the indirect object syntax, which tend to be rather obscure when encountered. See http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-01/msg01674.html for details.

Protected Methods

none.

Known Socket Options

These are the socket options known to the "Net::TCP" module itself:

"TCP_NODELAY" "TCP_MAXSEG" "TCP_RPTR2RXT"

Known Object Parameters

There are no object parameters registered by the "Net::TCP" module itself.

TIESCALAR

Tieing of scalars to a TCP handle is supported by inheritance from the "TIESCALAR" method of "Net::Gen". That method only succeeds if a call to a "new" method results in an object for which the "isconnected" method returns true, which is why it is mentioned in connection with this module.

Example:

     tie $x,Net::TCP,0,'finger' or die;
     $x = "-s\015\012";
     print $y while defined($y = $x);
     untie $x;
 
 

This is an expensive re-implementation of finger -s on many machines.

Each assignment to the tied scalar is really a call to the "put" method (via the "STORE" method), and each read from the tied scalar is really a call to the "getline" method (via the "FETCH" method).

Exports

default

none

exportable

"TCPOPT_EOL" "TCPOPT_MAXSEG" "TCPOPT_NOP" "TCPOPT_WINDOW" "TCP_MAXSEG" "TCP_MAXWIN" "TCP_MAX_WINSHIFT" "TCP_MSS" "TCP_NODELAY" "TCP_RPTR2RXT" "TH_ACK" "TH_FIN" "TH_PUSH" "TH_RST" "TH_SYN" "TH_URG"

tags

The following :tags are available for grouping related exportable items:

:sockopts

"TCP_NODELAY" "TCP_MAXSEG" "TCP_RPTR2RXT"

:tcpoptions

"TCPOPT_EOL" "TCPOPT_MAXSEG" "TCPOPT_NOP" "TCPOPT_WINDOW"

:protocolvalues

"TCP_MAXWIN" "TCP_MAX_WINSHIFT" "TCP_MSS" "TH_ACK" "TH_FIN" "TH_PUSH" "TH_RST" "TH_SYN" "TH_URG"

:ALL

All of the above exportable items.

THREADING STATUS

This module has been tested with threaded perls, and should be as thread-safe as perl itself. (As of 5.005_03 and 5.005_57, that's not all that safe just yet.) It also works with interpreter-based threads ('ithreads') in more recent perl releases.

SEE ALSO

Net::Inet(3), Net::Gen(3), Net::TCP::Server(3)

AUTHOR

Spider Boardman <spidb@cpan.org>