Control stript which is runing in background.

[jak]

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....