I have two files with some lines being the same.File A : command 1{    some code lines}command 2command 3command 4{    some code lines}File B :command 5command 3command 1{    some code lines}I'd like to have a final file containing this:command 1{    some code lines}command 2command 3command 4{    some code lines}command 5Order of lines is not relevant. Is there an existing tool (or a command) to do so? 
Is there a way to merge two files smartly?
files;merge