Method: IO#seek

Defined in:

io.c

#seek(amount, whence = IO::SEEK_SET) ⇒ 0

Seeks to a given offset anInteger in the stream according to the value of whence:

:CUR or IO::SEEK_CUR  | Seeks to _amount_ plus current position
----------------------+--------------------------------------------------
:END or IO::SEEK_END  | Seeks to _amount_ plus end of stream (you
                      | probably want a negative value for _amount_)
----------------------+--------------------------------------------------
:SET or IO::SEEK_SET  | Seeks to the absolute location given by _amount_

Example:

f = File.new("testfile")
f.seek(-13, IO::SEEK_END)   #=> 0
f.readline                  #=> "And so on...\n"

Returns:

• (0)

# File 'io.c', line 2138

static VALUE
rb_io_seek_m(int argc, VALUE *argv, VALUE io)
{
    VALUE offset, ptrname;
    int whence = SEEK_SET;

    if (rb_scan_args(argc, argv, "11", &offset, &ptrname) == 2) {
	whence = interpret_seek_whence(ptrname);
    }

    return rb_io_seek(io, offset, whence);
}