getting the exit status of a background processes

gururaj · 04-24-2006, 11:59 AM

Hi,
I want to get the exit code for all the background processes after the wait

#!/bin/sh
echo "Parallel Processes Start"
sleep a.sh &
sleep b.sh &
sleep 100 &
echo "Parallel Processes Created"
wait

can you please advise on this

Thanks in advance.

ataraxia · 04-24-2006, 05:47 PM

I took the "sleep" from in front of a.sh and b.sh - I don't know what you meant by it.

Code:

#!/bin/sh
echo "Parallel Processes Start"
a.sh &
apid=$!
b.sh &
bpid=$!
sleep 100 &
slpid=$!
echo "Parallel Processes Created"
wait apid
acode=$?
wait bpid
bcode=$?
wait slpid
slcode=$?
echo "a.sh code is $acode"
echo "b.sh code is $bcode"
echo "sleep code is $slcode"

gururaj · 04-25-2006, 12:39 AM

i am sorry, i typed wrongly the script

it should be as

#!/bin/sh
echo "Parallel Processes Start"
a.sh &
b.sh &
sleep 100 &
echo "Parallel Processes Created"
wait

here a.sh and b.sh are another shell scripts which has exit status as 0 when the scripts executed successfully and 1 for any abnormal termination.

now after wait i have to run c.sh only when both a.sh and b.sh should have returned 0.

sorry for the inconvineance

ataraxia · 04-25-2006, 01:15 PM

Ok, a few minor changes from my last post. You don't need the sleep at all, since the waits will cover it for you.

Code:

#!/bin/sh
echo "Parallel Processes Start"
a.sh &
apid=$!
b.sh &
bpid=$!
echo "Parallel Processes Created"
wait apid
acode=$?
wait bpid
bcode=$?
[ $acode -eq 0 ] && [ $bcode -eq 0 ] && c.sh

gururaj · 04-26-2006, 01:29 AM

Thanks ataraxia,

What if the b.sh finishes its execution well before a.sh,
can is still get the return code of b.sh ?

ataraxia · 04-26-2006, 06:21 PM

Quote:

Originally Posted by gururaj

Thanks ataraxia,

What if the b.sh finishes its execution well before a.sh,
can is still get the return code of b.sh ?

Yes. Since the waits are for specific PIDs, you will always get the right return code in the right variable. If b.sh finishes first, it will just make the second wait finish instantly.

gururaj · 04-27-2006, 06:59 AM

I think
acode=$? will get the return code of wait and not the return code of a.sh right. Is there any other way ??

ataraxia · 04-27-2006, 05:56 PM

Quote:

Originally Posted by gururaj

I think
acode=$? will get the return code of wait and not the return code of a.sh right. Is there any other way ??

The return code of wait is the return code of a.sh, according to the bash manpage.