A screen shot of Kompare
|Developer(s)||The Kompare Team|
Kompare is a free software graphical computer application which helps the user to compare two different text files or two directories. It is part of the KDE SC desktop environment and therefore primarily used on Linux and other Unix-like operating systems. Kompare does not actually compute the differences between the compared files itself, but is merely a graphical front end to the command line interface diff utility.
It is a standard KDE SC tool, it comes packaged with the kdesdk module.
Kompare was previously known as "kdiff".
Comparing text files 
As the above image shows, Kompare displays the two compared files next to each other in a way that corresponding lines are always positioned as near to each other as possible, independent of the position of the scrollbar. Lines that are different in the compared files are highlighted in both file views. Three different colors are used for highlighting, indicating whether the highlighted passage either
- exists in the first file but not in the second one (i.e. the highlighted passage has been deleted from the first file); or
- exists in the second file but not in the first one (i.e. it has been added to the first file); or
- exists in both files but is different (i.e. it has been changed since the first file had been created)
Other features of Kompare 
An incomplete list of features Kompare supports additionally to comparing text files follows.
Comparing directories 
When two directories are chosen to be compared instead of two text files, Kompare displays a directory tree for both selected directories, which contains only pairs of corresponding files and directories that are not equal in the two compared directories. Clicking on an entry displays a comparison of the two selected files.
Creating and applying patches 
Kompare is able to create a patch file which lists only the differences between two compared text files A and B. Further, Kompare can apply a patch file which was created this way to an original file A and, in this manner, recompute the contents of the corresponding file B. This is a comfortable utility for passing a corrected version of a file to a friend who already has an older version of the same file, because only the (relatively small) patch file has to be delivered and the receiver can generate the corrected file by applying the patch to the original file.
The patches created and applied by Kompare are compatible with patch files generated or applied by the command line interface diff utility, because Kompare is in fact merely a graphical front end to diff and the patches are created and applied by patch, which gets called by Kompare.
See also 
- Comparison of file comparison tools
- meld, KDiff3 - visualize differences very much like Kompare, but also allow merging files and editing details of the text.
- FileMerge presents file differences using a style very similar to Kompare.
- WinMerge, a similar free software tool for Microsoft Windows.