FM / IO

/usr/lib64/perl5/IO

Name	Size	Mode	Actions
Socket/	-	0755	rm
Dir.pm	5368	0644	edit dl rm
File.pm	4902	0644	edit dl rm
Handle.pm	17176	0644	edit dl rm
Pipe.pm	5472	0644	edit dl rm
Poll.pm	4539	0644	edit dl rm
Seekable.pm	2935	0644	edit dl rm
Select.pm	8350	0644	edit dl rm
Socket.pm	16049	0644	edit dl rm

Edit: /usr/lib64/perl5/IO/Seekable.pm (2935B)

package IO::Seekable;

=head1 NAME

IO::Seekable - supply seek based methods for I/O objects

=head1 SYNOPSIS

use IO::Seekable;
    package IO::Something;
    @ISA = qw(IO::Seekable);

=head1 DESCRIPTION

C<IO::Seekable> does not have a constructor of its own as it is intended to
be inherited by other C<IO::Handle> based objects. It provides methods
which allow seeking of the file descriptors.

=over 4

=item $io->getpos

Returns an opaque value that represents the current position of the
IO::File, or C<undef> if this is not possible (eg an unseekable stream such
as a terminal, pipe or socket). If the fgetpos() function is available in
your C library it is used to implements getpos, else perl emulates getpos
using C's ftell() function.

=item $io->setpos

Uses the value of a previous getpos call to return to a previously visited
position. Returns "0 but true" on success, C<undef> on failure.

=back

See L<perlfunc> for complete descriptions of each of the following
supported C<IO::Seekable> methods, which are just front ends for the
corresponding built-in functions:

=over 4

=item $io->seek ( POS, WHENCE )

Seek the IO::File to position POS, relative to WHENCE:

=over 8

=item WHENCE=0 (SEEK_SET)

POS is absolute position. (Seek relative to the start of the file)

=item WHENCE=1 (SEEK_CUR)

POS is an offset from the current position. (Seek relative to current)

=item WHENCE=2 (SEEK_END)

POS is an offset from the end of the file. (Seek relative to end)

=back

The SEEK_* constants can be imported from the C<Fcntl> module if you
don't wish to use the numbers C<0> C<1> or C<2> in your code.

Returns C<1> upon success, C<0> otherwise.

=item $io->sysseek( POS, WHENCE )

Similar to $io->seek, but sets the IO::File's position using the system
call lseek(2) directly, so will confuse most perl IO operators except
sysread and syswrite (see L<perlfunc> for full details)

Returns the new position, or C<undef> on failure.  A position
of zero is returned as the string C<"0 but true">

=item $io->tell

Returns the IO::File's current position, or -1 on error.

=back

=head1 SEE ALSO

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

=head1 HISTORY

Derived from FileHandle.pm by Graham Barr E<lt>gbarr@pobox.comE<gt>

=cut

use 5.006_001;
use Carp;
use strict;
our($VERSION, @EXPORT, @ISA);
use IO::Handle ();
# XXX we can't get these from IO::Handle or we'll get prototype
# mismatch warnings on C<use POSIX; use IO::File;> :-(
use Fcntl qw(SEEK_SET SEEK_CUR SEEK_END);
require Exporter;

@EXPORT = qw(SEEK_SET SEEK_CUR SEEK_END);
@ISA = qw(Exporter);

$VERSION = "1.10";
$VERSION = eval $VERSION;

sub seek {
    @_ == 3 or croak 'usage: $io->seek(POS, WHENCE)';
    seek($_[0], $_[1], $_[2]);
}

sub sysseek {
    @_ == 3 or croak 'usage: $io->sysseek(POS, WHENCE)';
    sysseek($_[0], $_[1], $_[2]);
}

sub tell {
    @_ == 1 or croak 'usage: $io->tell()';
    tell($_[0]);
}

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