coproc eperiments

coproc eperiments

[Meino Christian Cramer]

Hi,

 I am currenlty experimenting with the coproc command.

 If I am doing the "hello world"-version of coproc:

	coproc bc
	noglob echo 3*6 >&p
	read a <&p; echo $a

 Everthing is working fine.

 But if I am doing:

	coproc bc
	rxvt zsh &

	( and then in the new shell
	noglob echo 3*6 >&p
	Bad file descriptor

 As I think to know (*VERY* carefully) beside other things the
 filedescriptors of a parent process are inherited to the child
 process.

 Why is the zsh started by rxvt started by the first zsh not able to
 use &>p ?

 keep zshing!
 Meino

	

Re: coproc eperiments

[Peter Stephenson]

Meino Christian Cramer wrote:
>  But if I am doing:
> 
> 	coproc bc
> 	rxvt zsh &
> 
> 	( and then in the new shell
> 	noglob echo 3*6 >&p
> 	Bad file descriptor
> 
>  As I think to know (*VERY* carefully) beside other things the
>  filedescriptors of a parent process are inherited to the child
>  process.
> 
>  Why is the zsh started by rxvt started by the first zsh not able to
>  use &>p ?

I realise no one answered this...  It's not the intention that subshells
inherit coprocesses.  They will inherit fd's, but not any status
information that indicates the fd is associated with a coprocess.
In fact, the fd should probably be marked "close on exec" in this case.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070


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