IO::Seekable - supply seek based methods for I/O objects |
IO::Seekable - supply seek based methods for I/O objects
use IO::Seekable; package IO::Something; @ISA = qw(IO::Seekable);
IO::Seekable
does not have a constructor of its own as it is intended to
be inherited by other IO::Handle
based objects. It provides methods
which allow seeking of the file descriptors.
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.
undef
on failure.
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:
The SEEK_* constants can be imported from the Fcntl
module if you
don't wish to use the numbers 0
1
or 2
in your code.
Returns 1
upon success, 0
otherwise.
lseek(2)
directly, so will confuse most perl IO operators except
sysread and syswrite (see the perlfunc manpage for full details)
Returns the new position, or undef
on failure. A position
of zero is returned as the string "0 but true"
=head1 SEE ALSO
the perlfunc manpage, I/O Operators in the perlop manpage, the IO::Handle manpage the IO::File manpage
Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>
IO::Seekable - supply seek based methods for I/O objects |