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.
undefif 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.
See perlfunc for complete descriptions of each of the following
IO::Seekable methods, which are just front ends for the
corresponding built-in functions:
Seek the IO::File to position POS, relative to WHENCE:
The SEEK_* constants can be imported from the
Fcntl module if you
don't wish to use the numbers
2 in your code.
1 upon success,
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"
Derived from FileHandle.pm by Graham Barr <email@example.com>