Il 01/01/2021 06:23, Alan Bawden ha scritto:
jak <nos...@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....
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