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IO::Seekable(3)	       Perl Programmers	Reference Guide	       IO::Seekable(3)

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

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

DESCRIPTION
       "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.

       $io->getpos
	   Returns an opaque value that	represents the current position	of the
	   IO::File, or	"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.

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

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

       $io->seek ( POS,	WHENCE )
	   Seek	the IO::File to	position POS, relative to WHENCE:

	   WHENCE=0 (SEEK_SET)
		   POS is absolute position. (Seek relative to the start of
		   the file)

	   WHENCE=1 (SEEK_CUR)
		   POS is an offset from the current position. (Seek relative
		   to current)

	   WHENCE=2 (SEEK_END)
		   POS is an offset from the end of the	file. (Seek relative
		   to end)

	   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.

       $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 perlfunc for full
	   details)

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

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

SEE ALSO
       perlfunc, "I/O Operators" in perlop, IO::Handle IO::File

HISTORY
       Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>

perl v5.26.0			  2017-02-28		       IO::Seekable(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY

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