Errno - System errno constants
use Errno qw(EINTR EIO :POSIX);
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.
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 <[email protected]>
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.