coprocesses and bc

coprocesses and bc

[Matthias Kopfermann]

i have a book about the ksh shell.

there is an example about coprocesses that i try to get done
with the zsh 3.0 without success:

coproc bc

print -p "23*34"

read -p erg
echo $erg


my zsh (linux 2.029) sticks with read -p erg.
nothing is moving.

the same thing is no problem with the zsh 3.1 at aix 4.1.

so i am asking: what could be the reason that i have problems at home.
perhaps wrong setopt variables set?


-- 
Matthias

Re: coprocesses and bc

[Peter Stephenson]

Matthias Kopfermann wrote:
> coproc bc
> 
> print -p "23*34"
> 
> read -p erg
> echo $erg
> 
> 
> my zsh (linux 2.029) sticks with read -p erg.
> nothing is moving.

Try the following experiment: type 'bc | cat' at the keyboard,
then the sum on the following line.  If you don't get a message back
straight away, bc is buffering output when it's not going to a terminal.
My guess is that this is happening in Linux and not on your AIX machine.
If that's right, then it's not a shell problem (phew).  This would
certainly reflect my experience comparing Irix with SunOS 4.

-- 
Peter Stephenson <pws@ifh.de>       Tel: +49 33762 77366
WWW:  http://www.ifh.de/~pws/       Fax: +49 33762 77413
Deutsches Elektronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, Platanenallee 6, 15738 Zeuthen, Germany.