Clemens Anhuth wrote in a message to Erik Huelsmann:

 CA> as far as os/2 is concerned and afaik you can only access
 CA> whole files. 

No. You can lock a only a range, using (for example) DosSetFileLocks
function, and setting unlock file offset and unlock range to zero. 

 CA> but os/2 is no   multiuser-system and lacks the support for
 CA> record oriented file access and   locking mechanisms,
 CA> afaik...

That is partially true. You can lock records yourself, calculating what
range of file you have to lock... Lock time should be short in any case,
though...

\M 
--- timEd/2 1.01.g3+