errno(3pm)
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 nonzero 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
- 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.