Hello Thibault,
Please keep the mailing list in the CC list so that everyone can
participate and learn from the discussion. Thanks.
Thibault LE PAUL wrote:
> The problem was with a tee.
> Here is an example :
>
> rm /tmp/fifo1
> mkfifo /tmp/fifo1
> cat /tmp/fifo1|(head -20;cat >/dev/null)|sed 's/^/head &/' &
> #(cat /tmp/fifo1|sed -e '21,$d' -e 's/^/head &/') &
> #(cat /tmp/fifo1|awk 'FNR<21{print "head "$0}')&
> tee /tmp/fifo1|tail -20|sed 's/^/tail &/'
>
> It works with cat, I didn't think to it.
You have shown part of what you are trying. That is good. But I
don't see a problem with what you are showing. Please show us both
what you are expecting and also what you are seeing that you think is
a problem.
Using 'head -20' is problematic usage. I recommend avoiding it.
I tried this:
$ mkfifo fifo
$ cat fifo | head -n1 | sed 's/^/head &/' &
[1] 20056
$ printf "foo\nfoo\nfoo\n" > fifo
head foo
$
[1]+ Done cat fifo | head -n1 | sed 's/^/head &/'
$
That all seems reasonable to me. What problem are you seeing?
Bob
