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Errno

Perl 5 version 20.0 documentation
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Errno

NAME

Errno - System errno constants

SYNOPSIS

  1.     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:

  1.     use Errno;
  3.     unless (open(FH, "/fangorn/spouse")) {
  4.         if ($!{ENOENT}) {
  5.             warn "Get a wife!\n";
  6.         } else {
  7.             warn "This path is barred: $!";
  8.         } 
  9.     }

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:

  1.     if (exists &Errno::EFOO) {
  2.         $! = &Errno::EFOO;
  3.     }

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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