Fcntl: add more constants

[p5sagit/p5-mst-13.2.git] / ext / Fcntl / Fcntl.pm

package Fcntl;

=head1 NAME

Fcntl - load the C Fcntl.h defines

=head1 SYNOPSIS

    use Fcntl;
    use Fcntl qw(:DEFAULT :flock);

=head1 DESCRIPTION

This module is just a translation of the C F<fnctl.h> file.
Unlike the old mechanism of requiring a translated F<fnctl.ph>
file, this uses the B<h2xs> program (see the Perl source distribution)
and your native C compiler.  This means that it has a 
far more likely chance of getting the numbers right.

=head1 NOTE

Only C<#define> symbols get translated; you must still correctly
pack up your own arguments to pass as args for locking functions, etc.

=head1 EXPORTED SYMBOLS

By default your system's F_* and O_* constants (eg, F_DUPFD and O_CREAT)
are exported into your namespace.  You can request that the flock()
constants (LOCK_SH, LOCK_EX, LOCK_NB and LOCK_UN) be provided by using
the tag C<:flock>.  See L<Exporter>.

Please refer to your native fcntl() and open() documentation to see
what constants are implemented in your system.

=cut

use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $AUTOLOAD);

require Exporter;
require DynaLoader;
@ISA = qw(Exporter DynaLoader);
$VERSION = "1.02";
# Items to export into callers namespace by default
# (move infrequently used names to @EXPORT_OK below)
@EXPORT =
  qw(
     F_DUPFD F_GETFD F_GETLK F_SETFD F_GETFL F_SETFL F_SETLK F_SETLKW
     FD_CLOEXEC F_RDLCK F_UNLCK F_WRLCK
     O_CREAT O_EXCL O_NOCTTY O_TRUNC
     O_APPEND O_NONBLOCK
     O_NDELAY O_DEFER
     O_RDONLY O_RDWR O_WRONLY
     O_EXLOCK O_SHLOCK O_ASYNC O_DSYNC O_RSYNC O_SYNC
     F_SETOWN F_GETOWN
     );

# Other items we are prepared to export if requested
@EXPORT_OK = qw(
    LOCK_SH LOCK_EX LOCK_NB LOCK_UN
);
# Named groups of exports
%EXPORT_TAGS = (
    'flock' => [qw(LOCK_SH LOCK_EX LOCK_NB LOCK_UN)],
);

sub AUTOLOAD {
    my($constname);
    ($constname = $AUTOLOAD) =~ s/.*:://;
    my $val = constant($constname, @_ ? $_[0] : 0);
    if ($! != 0) {
	if ($! =~ /Invalid/) {
	    $AutoLoader::AUTOLOAD = $AUTOLOAD;
	    goto &AutoLoader::AUTOLOAD;
	}
	else {
	    my ($pack,$file,$line) = caller;
	    die "Your vendor has not defined Fcntl macro $constname, used at $file line $line.
";
	}
    }
    eval "sub $AUTOLOAD { $val }";
    goto &$AUTOLOAD;
}

bootstrap Fcntl $VERSION;

1;