SYS-SEEK(2) System Calls Manual SYS-SEEK(2)

seek - change file offset

include "sys.m";
sys := load Sys Sys->PATH;
seek:  fn(fd: ref FD, off: big, start: int): big;

Seek sets the 64-bit offset for the file associated with fd as follows:

If start is Sys->SEEKSTART, the offset is set to off bytes.
If start is Sys->SEEKRELA, the pointer is set to its current location plus off.
If start is Sys->SEEKEND, the pointer is set to the size of the file plus off.

The new file offset value is returned.

Seeking in a pipe is not allowed. Seeking in a directory is allowed only if the new offset is zero.

sys-intro (2), sys-open (2), bufio (2),