[inseparable changes from patch from perl5.003_11 to perl5.003_12]

[p5sagit/p5-mst-13.2.git] / ext / IO / lib / IO / File.pm

package IO::File;

=head1 NAME

IO::File - supply object methods for filehandles

=head1 SYNOPSIS

    use IO::File;

    $fh = new IO::File;
    if ($fh->open "< file") {
        print <$fh>;
        $fh->close;
    }

    $fh = new IO::File "> FOO";
    if (defined $fh) {
        print $fh "bar\n";
        $fh->close;
    }

    $fh = new IO::File "file", "r";
    if (defined $fh) {
        print <$fh>;
        undef $fh;       # automatically closes the file
    }

    $fh = new IO::File "file", O_WRONLY|O_APPEND;
    if (defined $fh) {
        print $fh "corge\n";
        undef $fh;       # automatically closes the file
    }

    $pos = $fh->getpos;
    $fh->setpos $pos;

    $fh->setvbuf($buffer_var, _IOLBF, 1024);

    autoflush STDOUT 1;

=head1 DESCRIPTION

C<IO::File> inherits from C<IO::Handle> and C<IO::Seekable>. It extends
these classes with methods that are specific to file handles.

=head1 CONSTRUCTOR

=over 4

=item new ([ ARGS ] )

Creates a C<IO::File>.  If it receives any parameters, they are passed to
the method C<open>; if the open fails, the object is destroyed.  Otherwise,
it is returned to the caller.

=back

=head1 METHODS

=over 4

=item open( FILENAME [,MODE [,PERMS]] )

C<open> accepts one, two or three parameters.  With one parameter,
it is just a front end for the built-in C<open> function.  With two
parameters, the first parameter is a filename that may include
whitespace or other special characters, and the second parameter is
the open mode, optionally followed by a file permission value.

If C<IO::File::open> receives a Perl mode string ("E<gt>", "+E<lt>", etc.)
or a POSIX fopen() mode string ("w", "r+", etc.), it uses the basic
Perl C<open> operator.

If C<IO::File::open> is given a numeric mode, it passes that mode
and the optional permissions value to the Perl C<sysopen> operator.
For convenience, C<IO::File::import> tries to import the O_XXX
constants from the Fcntl module.  If dynamic loading is not available,
this may fail, but the rest of IO::File will still work.

=back

=head1 SEE ALSO

L<perlfunc>, 
L<perlop/"I/O Operators">,
L<IO::Handle>
L<IO::Seekable>

=head1 HISTORY

Derived from FileHandle.pm by Graham Barr E<lt>F<bodg@tiuk.ti.com>E<gt>.

=head1 REVISION

$Revision: 1.5 $

=cut

require 5.000;
use vars qw($VERSION @EXPORT @EXPORT_OK $AUTOLOAD);
use Carp;
use Symbol;
use SelectSaver;
use IO::Handle qw(_open_mode_string);
use IO::Seekable;

require Exporter;
require DynaLoader;

@ISA = qw(IO::Handle IO::Seekable Exporter DynaLoader);

$VERSION = sprintf("%d.%02d", q$Revision: 1.5 $ =~ /(\d+)\.(\d+)/);

@EXPORT = @IO::Seekable::EXPORT;

sub import {
    my $pkg = shift;
    my $callpkg = caller;
    Exporter::export $pkg, $callpkg, @_;

    #
    # If the Fcntl extension is available,
    #  export its constants for sysopen().
    #
    eval {
	require Fcntl;
	Exporter::export 'Fcntl', $callpkg, '/^O_/';
    };
}


################################################
## Constructor
##

sub new {
    my $type = shift;
    my $class = ref($type) || $type || "IO::File";
    @_ >= 0 && @_ <= 3
	or croak "usage: new $class [FILENAME [,MODE [,PERMS]]]";
    my $fh = $class->SUPER::new();
    if (@_) {
	$fh->open(@_)
	    or return undef;
    }
    $fh;
}

################################################
## Open
##

sub open {
    @_ >= 2 && @_ <= 4 or croak 'usage: $fh->open(FILENAME [,MODE [,PERMS]])';
    my ($fh, $file) = @_;
    if (@_ > 2) {
	my ($mode, $perms) = @_[2, 3];
	if ($mode =~ /^\d+$/) {
	    defined $perms or $perms = 0666;
	    return sysopen($fh, $file, $mode, $perms);
	}
        $file = "./" . $file unless $file =~ m#^/#;
	$file = _open_mode_string($mode) . " $file\0";
    }
    open($fh, $file);
}

1;