seek filehandle, offset, whence
Positions the file pointer for filehandle, just
like the fseek(3) call of standard I/O. The first position in a
file is at offset 0, not offset 1, and offsets refer to byte positions,
not line numbers.
The function returns 1 upon success, 0 otherwise.
For handiness, the function can calculate offsets from various file
positions for you. The value of whence specifies which of three file
positions your offset is relative to: 0, the beginning of
the file; 1, the current position in the file; or 2, the
end of the file. offset may be negative for a whence of
1 or 2.