Le Friday 11 September 2015 à 20:23 +0000, Thorsten Glaser a écrit :
> Dixi quod…
>
> >I think coprocesses are pretty usable for this in almost all cases
> >(I did have one where they weren’t, but you can still often background
> >a part, then play with fd redirection).
>
> Another thing that may help you, if it’s absolutely needed:
>
> Before we had ${PIPESTATUS[*]} I wrote things like this:
>
> foo | (bar; echo $? >bar.rv) | baz
>
> Similarily, you can do tricks with high file descriptors.
>
> x=$( (echo foo | (tr a-z A-Z >&4) | (echo bla >&5)) 4>&1) 5>&1
> echo x=$x
>
> This gives:
>
> bla
> x=FOO
"Nice" :]
> Both not as efficient as direct variable assignment, but…
>
> And let's not forget using…
> while …; do …; done <foo
> … instead of…
> cat foo | while …; do …; done
> … (which is cat abuse anyway).
Amen. I've been working with a lot of bash scripts and I yell each time
I see the "cat foo |" construct.
> Often, some not-so-basic or more modern scripting approaches
> can eliminate the need for a construct like you were asking for.
I will check with the customer. The example they provided was clearly
made up to illustrate the problem (and I do appreciate when customers
make the problem easy to understand) so I don't know exactly what their
actually script is doing.
--
Jean Delvare
SUSE L3 Support
