IO::Select - phpMan

NAME
    IO::Select - OO interface to the select system call

SYNOPSIS
        use IO::Select;

        $s = IO::Select->new();

        $s->add(\*STDIN);
        $s->add($some_handle);

        @ready = $s->can_read($timeout);

        @ready = IO::Select->new(@handles)->can_read(0);

DESCRIPTION
    The "IO::Select" package implements an object approach to the system
    "select" function call. It allows the user to see what IO handles, see
    IO::Handle, are ready for reading, writing or have an exception pending.

CONSTRUCTOR
    new ( [ HANDLES ] )
        The constructor creates a new object and optionally initialises it
        with a set of handles.

METHODS
    add ( HANDLES )
        Add the list of handles to the "IO::Select" object. It is these
        values that will be returned when an event occurs. "IO::Select"
        keeps these values in a cache which is indexed by the "fileno" of
        the handle, so if more than one handle with the same "fileno" is
        specified then only the last one is cached.

        Each handle can be an "IO::Handle" object, an integer or an array
        reference where the first element is an "IO::Handle" or an integer.

    remove ( HANDLES )
        Remove all the given handles from the object. This method also works
        by the "fileno" of the handles. So the exact handles that were added
        need not be passed, just handles that have an equivalent "fileno"

    exists ( HANDLE )
        Returns a true value (actually the handle itself) if it is present.
        Returns undef otherwise.

    handles
        Return an array of all registered handles.

    can_read ( [ TIMEOUT ] )
        Return an array of handles that are ready for reading. "TIMEOUT" is
        the maximum amount of time to wait before returning an empty list
        (with $! unchanged), in seconds, possibly fractional. If "TIMEOUT"
        is not given and any handles are registered then the call will block
        indefinitely. Upon error, an empty list is returned, with $! set to
        indicate the error. To distinguish between timeout and error, set $!
        to zero before calling this method, and check it after an empty list
        is returned.

    can_write ( [ TIMEOUT ] )
        Same as "can_read" except check for handles that can be written to.

    has_exception ( [ TIMEOUT ] )
        Same as "can_read" except check for handles that have an exception
        condition, for example pending out-of-band data.

    count ()
        Returns the number of handles that the object will check for when
        one of the "can_" methods is called or the object is passed to the
        "select" static method.

    bits()
        Return the bit string suitable as argument to the core select()
        call.

    select ( READ, WRITE, EXCEPTION [, TIMEOUT ] )
        "select" is a static method, that is you call it with the package
        name like "new". "READ", "WRITE" and "EXCEPTION" are either "undef"
        or "IO::Select" objects. "TIMEOUT" is optional and has the same
        effect as for the core select call.

        If at least one handle is ready for the specified kind of operation,
        the result will be an array of 3 elements, each a reference to an
        array which will hold the handles that are ready for reading,
        writing and have exceptions respectively. Upon timeout, an empty
        list is returned, with $! unchanged. Upon error, an empty list is
        returned, with $! set to indicate the error. To distinguish between
        timeout and error, set $! to zero before calling this method, and
        check it after an empty list is returned.

EXAMPLE
    Here is a short example which shows how "IO::Select" could be used to
    write a server which communicates with several sockets while also
    listening for more connections on a listen socket

        use IO::Select;
        use IO::Socket;

        $lsn = IO::Socket::INET->new(Listen => 1, LocalPort => 8080);
        $sel = IO::Select->new( $lsn );

        while(@ready = $sel->can_read) {
            foreach $fh (@ready) {
                if($fh == $lsn) {
                    # Create a new socket
                    $new = $lsn->accept;
                    $sel->add($new);
                }
                else {
                    # Process socket

                    # Maybe we have finished with the socket
                    $sel->remove($fh);
                    $fh->close;
                }
            }
        }

AUTHOR
    Graham Barr. Currently maintained by the Perl Porters. Please report all
    bugs to <perlbug AT perl.org>.

COPYRIGHT
    Copyright (c) 1997-8 Graham Barr <gbarr AT pobox.com>. All rights reserved.
    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

Generated by phpMan Author: Che Dong On Apache Under GNU General Public License - MarkDown Format
2026-05-21 22:09 @216.73.216.105 CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)