Hi vennila, It's not that difficult a problem, break it into manageable sections

• open the file words.txt
• while the file is open examine each word
• if a is present and e is present and i is present and o is present and u is present
• print the current word, or push it onto an array you will return when you are finished

Now each of those items is doable in a single command (or less), try and code it up and feel free to ask if you have a problem with your Perl code rather than your basic algorithm.