apt-get install with some options and scripting results in nice pattern for package installation. For example, this can help to make your script FAI – ready, because this tool is very sensitive to any ‘chaotic’ script output.

What we need:

1. Function to check the last operation success or die quitOnError
2. Suppress the apt-get user interaction --force-yes --yes
3. Suppress any standard output (we only need to know if it worked or not) > /dev/null 2>&1 ;

 
Install the improved random number generator for Linux (rng-tools), clean quit if no install was possible.

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#!/bin/bash
 
function quitOnError {
   if [ $? -gt 0 ]
   then
     echo -e "\n\n $@ ...FAIL"
     exit 10
   else
     echo "$@ ...OK"
   fi
}
 
apt-get install --force-yes --yes rng-tools > /dev/null 2>&1 ;
quitOnError "Installing rng tools now"
 
echo "rng tools installed, /etc/init.d/rng-tools start to increase you
linux system entropy level"