I need to find an automated way to solve the following problems; if you can be of help in something, I'd appreciate your suggestions:

1- A software to merge together multiple txt files (a large number, let's suppose 200) in a whole one without losing data.

2- A software to change in bulk the format of many files at once (i.e. 200). It's not a real conversion, it should simple add .txt at the bottom of each of them, nothing more and they'd work for me.

3- A software to extract thousands of domains (various tlds, it should not pay attention to the tld) from a big txt file containing a lot of unuseful text too. Domains doesn't begin with www. so it should reknow them by word.xxx.

Thanks again for trying to help.