[SOLVED] named hints update script

[matt81]

I need help getting this bourne shell script working properly. This script I found online while reading some tutorials on getting a caching name server running, which is supposed to update the rootserver hints file.

The below case statement always returns that the hints file has failed. Even though when I check the file it looks normal and I can see the NOERROR status in the returned header.

dig (at)e.root-servers.net . ns >root.hints.new 2> errors

 case `cat root.hints.new` in
   *NOERROR*)
        # It worked
        :;;
   *)
        echo "Subject: The root.hints file update has FAILED."
        echo
        echo "The root.hints update has failed"
        echo "This is the dig output reported:"
        echo
        cat root.hints.new errors
        exit 1
        ;;
 esac

I have also been wanting to turn these case statements into if statements if anyone could help me with the syntax for that. I don't typically like to use case statements when there is usually only 1 or 2 possible results. The problem I'm having here is that I can't seem to put command output into a string/variable. See the code below for an example of my intentions.

#Code to check if named is running.
status = 'rndc status | grep server'
if [ $status != 'server is up and running' ]
echo "Named is not running!"
echo "Exiting."
exit 0
fi

Maybe it's just me but I think the if statement looks cleaner than the case statement used in the original script.

Extra information:
I'm running this on FreeBSD 8.2-RELEASE.
The caching name server is working with no problems.

[Cabhan]

In your case statement, the reason that it always returns error is because the input is handled line-by-line. So it looks at the first line of root.hints.new. If that line matches the glob *NOERROR*, then it says it works. However, if that line doesn't, then it goes to the error case.

A better way of doing something like that would be:

if grep -q NOERROR root.hints.new; then
    # It worked
else
    # It failed
fi

Here we search the file for the string "NOERROR", and if it exists, we say that it worked. Some things to note:

1) grep -q means that grep doesn't output anything, and just exits with status 0 if the string was found, and nonzero otherwise.

2) We don't use if [ ... ], but instead just if .... This is because you can always just if a command; if the command exits with status 0 (success), it is considered true.

In your second example, the problem is your use of single quotes instead of backticks. Also, instead of backticks, you can use $(...). This is sometimes preferred because it is easier to distinguish from single quotes.

[matt81]

Much appreciated Cabhan! :D

Here's the full script which will need very little editing for anyone who wishes to use it. I put in full file paths so you can run the script from anywhere. Comments or suggestions are welcome.

#!/bin/sh
#
#Update named hints file
#Make a cron entry and forget about it!

#Check if named is running
echo "Checking if named is running..."

if `rndc status | grep -q "server is up and running"`
then
echo "Named is running!"
else
echo "Named is NOT running!"
echo "Exiting."
exit 0
fi

#Check for internet connection
echo "Checking if we are online..."

if `ping -c 1 <external ip> | grep -q "100.0% packet loss"`;
then
echo "We are not online!"
echo "Could not ping external server!"
echo "Exiting."
exit 1
else
echo "We are online!"
fi

#Create root.hints file

echo "Creating /etc/namedb/root.hints.new..."
dig @a.root-servers.net . ns > /etc/namedb/root.hints.new

if `cat /etc/namedb/root.hints.new | grep -q "NOERROR"`;
then
echo "File creation successful!"
echo "Replacing old file with updated information..."
chmod 644 /etc/namedb/root.hints.new
cp /etc/namedb/root.hints /etc/namedb/root.hints.old
cp /etc/namedb/root.hints.new /etc/namedb/root.hints
rm -f /etc/namedb/root.hints.new
echo "Restarting Named..."
/etc/rc.d/named onerestart
else
echo "The root.hints file update has FAILED!"
echo "Printing dig output..."
cat /etc/namedb/root.hints.new
echo "Exiting."
exit 1
fi

echo "Update Complete!"
exit 0

I wasn't able to just copy and paste my script since the server it's on doesn't have X running or a web browser so there might be a mistake but I don't see any after reading it 2x.

This thread can be renamed to SOLVED.
Thank you.