Kdiff3 is an open-source script that can be used in conjunction with the Kdiff4 suite of tools for the Linux kernel. In addition to its primary use being in the Linux kernel, it has also been incorporated into Windows as "ki_diff.c" (the file is actually in Linux). It is meant to be used as an easy way to compare two different files on Linux by allowing the user to select two different lines in a file and then comparing the differences between the two. The major difference is that the file to be compared must already exist as a file in the Linux kernel and the user must provide a script that will execute the necessary command line switches to create the new file.
Kdiff3 is a script designed to merge multiple files or directory structures into a single file. Not only does this make it useful for developers and system administrators, it also gives an extra feel of usability when comparing files in a directory when comparing with other systems. One thing to note when using kdiff3, is that there is an optional parameter called -depth which when specified will cause kdiff3 to show the differences line by line and character by character. While the purpose of this is to allow people to more easily compare input files when developing, it can also be useful when trying to merge files from different platforms.
A simple way to try out kdiff3 on your Linux system is to simply cd into the kdiff3 directory where you would like to run kdiff3, then execute the file. You may want to first download utf-8 and verify if your keyboard layout will properly display the characters displayed by kdiff3. Once you have this check, you should be good to go. To reiterate, if you have any problems or difficulties running kdiff3 simply cd into the kdiff3 directory, then execute the file. If the file ends up having problems, simply re-run the command and it should work just fine. This is the easiest and most straight forward way to use a Linux merge tool to re-merge your files between different platforms.