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.