Shell Programming and Scripting

Hello,

Two child processes work at the same time because they communicate one another. In KSH, does it exist a good way to suspend a parent process until one of the two child processes stops. It seems that the command 'wait' works well for one process but for two processes, it suspends the parent process until all the background child processes stop.
If a command or a C-code could return a status as well, that will be more better.


thanks

So you have two child processes and one parent process.

Create a pipe and have a "write to pipe" in each of the child processes
as the last statement in the child process.

and you have only one "read from pipe" in the parent process. so whichever child completes first, it will write to the pipe and the parent process will finish the read immediately.

How about using signal?
Would it be convenient that both child processes send a SIGUSR1 to the parent before end and that the parent has a sig handler which terminates itself?
Tom

#!/bin/ksh

start_first_child.sh &
start_second_child.sh &

while [ $(jobs | wc -l) -gt 0 ] ; do
sleep 1
done

exit 0

Hope this helps

bakunin

Thanks for the reply but I don't undertand what you mean by "write to pipe" or "read from pipe". Could you give me a practical example, please?

Thanks

Thanks for the reply. Do you know a good way to get the status of the stopped child process. In case of error, the other child process could become a zombi process (consequently, I'll do a 'kill -9' on it). Notice that I won't do it if the stopping is normal.

Thanks for the reply. Could you give me a practical example, please?. Could I get the status of the stopped child process with this method?