errno(3)

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!0;
} else {
warn "This path is barred: $!";
}
}
If a specified constant "EFOO" does not exist on the sys
tem, $!{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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