You should try
vimdiff file1 file2
Ex :
You can select lines (from command mode to visual mode) with shift+v, copy with yy, paste with p and switch into files with ctrl+ww
Pregunta
kdiff3 is a GUI diff tool that allows you to create a diff of two/three files and selectively choose which lines make up the merged file. Is there a command-line equivalent?
Solución
You should try
vimdiff file1 file2
Ex :
You can select lines (from command mode to visual mode) with shift+v, copy with yy, paste with p and switch into files with ctrl+ww
Otros consejos
Yes, vimdiff (quick tutorial linked) is quite good at it. Being part of VIM, you will have to learn the key strokes you need to accept or refuse changes.