Errno.3pm

Langue: en

Autres versions - même langue

Version: 2001-09-21 (openSuse - 09/10/07)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

Errno - System errno constants

SYNOPSIS


    use Errno qw(EINTR EIO :POSIX);

DESCRIPTION

"Errno" defines and conditionally exports all the error constants defined in your system "errno.h" include file. It has a single export tag, ":POSIX", which will export all POSIX defined error numbers.

"Errno" also makes "%!" magic such that each element of "%!" has a non-zero value only if $! is set to that value. For example:


    use Errno;





    unless (open(FH, "/fangorn/spouse")) {

        if ($!{ENOENT}) {

            warn "Get a wife!\n";

        } else {

            warn "This path is barred: $!";

        } 

    }

If a specified constant "EFOO" does not exist on the system, $!{EFOO} returns "". You may use "exists $!{EFOO}" to check whether the constant is available on the system.

CAVEATS

Importing a particular constant may not be very portable, because the import will fail on platforms that do not have that constant. A more portable way to set $! to a valid value is to use: 

    if (exists &Errno::EFOO) {

        $! = &Errno::EFOO;

    }

AUTHOR

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