Re:

> Is it possible to change a file limit after the creation of that file.
> The goal is to increase it in a C routine when, for example,
> when the file is 80% full.

No and yes.

The easy answer is "no", it isn't possible to increase the limit of a file.
With that answer, you may want to try creating the file with a large initial
limit, and never reducing that limit (so you never have to increase it).

The hard answer is "yes", there's an undocumented MPE routine that
can increase the file limit ... but your code must be privileged to
call it, and no one may have the file open at the time.
If you're interested in that routine, I'd suggest filing an enhancement
request to get a documented & supported access to it.

--
Stan Sieler                                          [log in to unmask]
                                     http://www.allegro.com/sieler.html