How to make two different files (their contents) equal using terminal in Linux? Suppose i have a file A in which the content is Hello world and i have a file B in which the content is Hello worlds. Now we find the difference between the 2 files using the diff or sdiff utility. Now i want to append the contents of the 2 different files into a single file or make the two different files (their contents) equal using terminal or any other utility.