I need scripting help. I have a unix Korns shell running sub-scripts that sometimes return with error. I want to capture the returncodes to a file and exit the parent script with returncode=0.

All you need to do is to explicitly exit with "exit 0" such as:

#!/bin/sh
subscript1.sh
exit 0

If you omit that exit, then the main script will exit with the exit code of the last command that it ran - in this case the exit code of subscript1.sh.

If you do something like:

#!/bin/sh
subscript1.sh
print "exit code of subscript1.sh was $?"

the main script will print the exit code of the sub-script, but it will then exit with a status of zero, which was the status of the successful print command.

If you want to test the status of a sub-script, then exit using that code, you need to capture it first:

#!/bin/sh
subscript1.sh
rc=$?
if [ $rc -eq 0 ] ; then
print "subscript1.sh was successful"
else
print "subscript1.sh was NOT successful"
fi
exit $rc