interactive/visual merge tool for console?
Solution 1:
Ah just found out about vimdiff. It pretty much does what I was looking for. here's a quick guide
Solution 2:
You can use vim -d file1 file2 for that.
Solution 3:
sdiff, a classic command line tool which shows text file differences side by side, also has an interactive merge mode. Use it by running
$ sdiff -o output.txt input1.txt input2.txt
It is the default interactive command line merge tool used by Gentoo Linux' etc-update utility.
Advantages over vimdiff are ubiquitous availability and much simpler handling.