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
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.
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