Comparing two IP Addresses in Bash

Question

I am trying to find if two ip addresses are the same or not. I admit that I am new with bash, but I see no reason this would not work:

if [[ "$IPAddress" != "$OLDIPAddress" ]]
then
  echo "IP Not the Same"
else
  echo "IP Same"
fi

For testing purposes, I have even hard coded the values for the two variables, and they still don't show up as the same. I know you don't always see your own typos, but I do not see why this would not work. Any ideas?

Answer 1

While your command should work, you can use the simple test operator (just a single bracket). The advantage is that it will work with any (POSIX) shell. However, the [[ operator should work too.

Can you reproduce this little example? (Should output 'yes'):

IPAddress="127.0.0.1"
OLDIPAddress="127.0.0.1"

if [ "$IPAddress" != "$OLDIPAddress" ] ; then 
    echo "no"
else
    echo "yes"
fi