SEEK(II) 8/5/73 SEEK(II)
NAME
seek - move read/write pointer
SYNOPSIS
(seek = 19.)
(file descriptor in r0)
sys seek; offset; ptrname
seek(fildes, offset, ptrname)
DESCRIPTION
The file descriptor refers to a file open for reading or
writing. The read (resp. write) pointer for the file is set
as follows:
if ptrname is 0, the pointer is set to offset.
if ptrname is 1, the pointer is set to its current
location plus offset.
if ptrname is 2, the pointer is set to the size of the
file plus offset.
if ptrname is 3, 4 or 5, the meaning is as above for 0, 1
and 2 except that the offset is multiplied by 512.
If ptrname is 0 or 3, offset is unsigned, otherwise it is
signed.
SEE ALSO
open(II), creat(II)
DIAGNOSTICS
The error bit (c-bit) is set for an undefined file
descriptor. From C, a -1 return indicates an error.