Errno - System errno constants
use Errno qw(EINTR EIO :POSIX);Errno defines and conditionally exports all the error constants defined in your systemerrno.h include file. It has a single export tag,:POSIX, which will export all POSIX defined error numbers.
On Windows,Errno also defines and conditionally exports all the Winsock error constants defined in your systemWinError.h include file. These are included in a second export tag,:WINSOCK.
Errno also makes%! magic such that each element of%! has a non-zero value only if$! is set to that value. For example:
my $fh;unless (open($fh, "<", "/fangorn/spouse")) { if ($!{ENOENT}) { warn "Get a wife!\n"; } else { warn "This path is barred: $!"; } }If a specified constantEFOO does not exist on the system,$!{EFOO} returns"". You may useexists $!{EFOO} to check whether the constant is available on the system.
Perl automatically loadsErrno the first time you use%!, so you don't need an explicituse.
Importing a particular constant may not be very portable, because the import will fail on platforms that do not have that constant. A more portable way to set$! to a valid value is to use:
if (exists &Errno::EFOO) { $! = &Errno::EFOO;}Graham Barr <gbarr@pobox.com>
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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