NAME

SYNOPSIS

    use Errno qw(EINTR EIO :POSIX);

DESCRIPTION

On Windows, "Errno" also defines and conditionally exports all the Winsock error constants defined in your system WinError.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 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.

Perl automatically loads "Errno" the first time you use "%!", so you don't need an explicit "use".

CAVEATS

    if (exists &Errno::EFOO) {
        $! = &Errno::EFOO;
    }

AUTHOR

COPYRIGHT