Shell Programming and Scripting

Hey, I have been fighting with this SIMPLE script for a while, and almost going to crazy!!

what I am doing is just get the DNS name for an IP, then echo the result,

under bash shell, I can do this using command line, without any problem,

$ a=`/usr/sbin/dig +short -x 216.239.37.104`
$ echo $a
va-in-f104.google.com.

Ok, so I wrote this in a script, ran it, no problem,

BUT , as long as I use cron to run this simple script, it give me nothing!

$ more /tmp/test.sh
#!/bin/bash
a=`/usr/sbin/dig +short -x 216.239.37.104`
echo "just confirm crontab execute this script" > /tmp/result
echo $a >> /tmp/result

$ more /tmp/result
just confirm crontab execute this script

$

what is the problem?

Hi,

I did encounter a similar problem previously. (ie, i can run the script manually, but it does not run in cron)

Perhaps you can try:
1. chmod the script, say try to allow all to read,write,exec ( i know its dangerous, but if it works, you can narrow it down to permission, maybe can try to chmod to 750, or something)
2.Set your environment. ( because when you log in to run manually, somehow the system knows that its you, but when you do it in cron, the system does not. I am not sure of the exact details, though)