bash-3.2$ cat c1
* * * * * cmd 1
* * * * * cmd 2
* * * * * cmd 3
bash-3.2$ cat c2
* * * * * cmd 4
* * * * * cmd 5
* * * * * cmd 6
* * * * * cmd 1
bash-3.2$ 
bash-3.2$ bash c.sh
* * * * * cmd 4
* * * * * cmd 5
* * * * * cmd 6
bash-3.2$ 
bash-3.2$ 
bash-3.2$ cat c.sh
#!/bin/bash
DIFF=$(comm <(sort c1) <(sort c2) | awk -F "\t" 'length($2)>0{print $2}' )
if [ "${DIFF}" != "" ]
then
        IFS=$"\n";
        echo ${DIFF}
fi