jak <nos...@please.ty> writes:
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....
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.
--
Alan Bawden
--
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