Re: [Caml-list] no tell on files?

[Ed L Cashin <ecashin@uga.edu>]

Chris Hecker <checker@d6.com> writes:

> There appears to be no "tell" function on pervasives streams or Unix
> file descriptors.  Is there a reason for this?  The combination of
> that plus the lack of a pervasives relative seek makes it hard to move
> around in files without keeping parallel information.

Seek is tell!  The program below gives this output:

  ecashin@meili seek-tell$ ./a.out 
  read 10 chars: " Unix.SEEK"



let main = 
  let fd = Unix.openfile "main.ml" [Unix.O_RDONLY] 0 in
  let end_pos = Unix.lseek fd 0 Unix.SEEK_END in
  let half_pos = Unix.lseek fd (end_pos/2) Unix.SEEK_SET and
      buf = String.create 1024 in
  Printf.printf "read %d chars: \"%s\"\n"
    (UnixLabels.read fd ~buf ~pos:0 ~len:10)
    buf  
;;

main

-- 
--Ed L Cashin            |   PGP public key:
  ecashin@uga.edu        |   http://noserose.net/e/pgp/
-------------------
To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr
Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/
Beginner's list: http://groups.yahoo.com/group/ocaml_beginners