Control stript which is runing in background.
jak
nospam at please.ty
Sat Jan 2 02:55:14 EST 2021
Il 02/01/2021 01:07, Alan Bawden ha scritto:
> jak <nospam at please.ty> writes:
>
> Il 01/01/2021 06:23, Alan Bawden ha scritto:
> > jak <nospam at please.ty> writes:
> >
> > Running the command:
> >
> > $ cat bible.txt > cmdpipe & cat bible.txt > cmdpipe & cat bible.txt > cmdpipe
> >
> > the three texts do not mix....
> >
> > The three texts do not mix as long at the contents of bible.txt is short
> > enough (and provided `cat' only calls `write' once). In the POSIX
> > specification, the manual page for the `write' system call describes
> > writing to a pipe or FIFO as follows:
> >
> > Write requests of {PIPE_BUF} bytes or less shall not be interleaved
> > with data from other processes doing writes on the same pipe. Writes
> > of greater than {PIPE_BUF} bytes may have data interleaved, on
> > arbitrary boundaries, with writes by other processes, whether or not
> > the O_NONBLOCK flag of the file status flags is set.
> >
> Ok. And...
> ...Running the command:
>
> $ cat bible.txt > cmdpipe & cat bible.txt > cmdpipe & cat bible.txt > cmdpipe
>
> the three texts do not mix....
>
> Saying it again doesn't make it any more true. If bible.txt is large
> enough, they most definitely DO mix! Just to make sure I wasn't missing
> something, I tested your exact command before I sent my previous reply.
> They mixed.
>
This is really strange. On which system did you test? unix, linux or a
surrogate (cygwin, msys)? I asked this because bible.txt is 4.25MB size
(https://github.com/mxw/grmr/blob/master/src/finaltests/bible.txt)...
and the OP needs to send only commands (I hope smaller than the bible).
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