MirBSD manpage: Errno(3p)

ext::Errno::ErrnoPerl3Programmers Referenext::Errno::Errno_pm(3p)

NAME

     Errno - System errno constants

SYNOPSIS

         use Errno qw(EINTR EIO :POSIX);

DESCRIPTION

     "Errno" defines and conditionally exports all the error con-
     stants 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.

perl v5.8.8                2005-02-05                           1