while read scripting trick
Posted by Peter Burkholder Tue, 13 Mar 2007 00:44:00 GMT
I saw this mentioned on the dc-sage email list but missed the particular example, until Sweth Chandramouli posted the following example for testing whether nameservers in /etc/resolv.conf are actually working:
#!/bin/sh
while read TOKEN IP ; do
case $TOKEN in nameserver )
echo "Testing DNS query against $IP: `dig -x 127.0.0.1 @$IP | grep ';; ->>'`" |\
logger -p local3.info -t check_dns ;;
esac
done < /etc/resolv.conf
Nice trick, although I’d like to cat the input into while at the top:
cat /etc/resolv.conf |
while ...
Oh yes, I have a new job. Director of System and Network Administration at EchoDitto, which is a topic meriting several blog posts.
