I think it would be better to get some more details before we go offering "solutions" based on guesswork.
Specifically, "merge" is a word that can have many different interpretations. The cat
command given above simply appends the second file after the first one. But if you mean something that intersperses lines, removes duplicates, or what, you're going to have to detail that.
So give us an actual example of what you need to do. Post the input texts and the desired output. And don't forget to use [code][/code]
tags to protect the formatting.
A few other details, like what this mysterious "program" is, might help too. Instead of posting vague descriptions, try reading How To Ask Questions The Smart Way
, and give us some specifics. Thanks!