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Manpages ErrnoSection: Perl Programmers Reference Guide (3perl)Updated: 2001-03-03 Index Return to Main Contents NAMEErrno - System errno constantsSYNOPSISuse 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. CAVEATSImporting 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; } AUTHORGraham Barr <gbarr@pobox.com>COPYRIGHTCopyright (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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