Errno(3pm) Perl Programmers Reference Guide 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 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!
";
} 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.
perl v5.18.2 2017-10-07 Errno(3pm)