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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!\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.

Index for Section 3

Alphabetical listing for E

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