
seek(+Stream, +Offset)

   The pointer in stream Stream is offset Offset from the start of the file

Arguments
   Stream              Stream handle or alias (atom)
   Offset              Integer or the atom end_of_file.

Type
   Stream I/O

Description
   Moves the file pointer to offset Offset from the start of the file
   opened.  It is an error if Stream is not a stream or if Offset is not an
   integer or the atom 'end_of_file'.


   seek/2 seeks to the end of the file when Offset is instantiated to
   end_of_file.


   Only file and string streams are seekable.
   seek/2 has no effect on the null stream, it always succeeds.



Modes and Determinism
   seek(+, +) is det

Exceptions
     4 --- Either Stream or Offset is uninstantiated.
     5 --- Offset is instantiated, but not to an integer or the atom end_of_file.
     5 --- Stream is instantiated, but not to an atom or a stream handle.
     6 --- Offset is a negative integer or greater than the file length.
   192 --- Stream is not seekable.
   193 --- Stream is an illegal stream specification.

Examples
   
Success:
      seek(0, null). % does not modify, only succeeds

      ?- open(file1,update,S), write(S,hello),
         seek(S,3), read(S,T), close(S).
      T = lo
      yes.

Error:
      seek( Offset,7).      (Error 4).
      seek("7", 2).         (Error 5).
      seek(7, -1).          (Error 6).
      seek( 0,input).       (Error 192).
      seek(-1, 0).          (Error 193). % does not exist


See Also
   at / 2, at_eof / 1, set_stream_property / 3
