Errno(3) Perl Programmers Reference Guide Errno(3)NAMEErrno - 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: $!";
}
}
If a specified constant "EFOO" does not exist on the sys
tem, "$!{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.
2001-03-18 perl v5.6.1 Errno(3)