Re: [9fans] trying to understand how fork/pipe a filtering program

["\"Nils O. Selåsdal\"" <noselasd@asgaard.homelinux.org>]

Axel Belinfante wrote:
> after the suggestion of resample(1) some days ago
> I've tried run it as a filter from another program.
> this other program is non-threaded; for testing all
> it does is call initdraw and read an image file
> after which the resample routine is called.
> 
> in my resample routine it seems I need a call to sleep
> to avoid the resample program to hang (in Pread).
> (replacing the sleep by a fprint(2, "something\n") works too).
> 
> I'm just trying to understand what goes on -
> is this the way to do this? if not, what am I missing?
> I'm sorry if it is something obvious; I'm just trying to learn.

Remember to close the pipe ends you don't need in the respective
parent/child, as well as the original pipes after dup'ing them.