Patch (Unix)

Patch is Unix computer program that applies textual difference between two programs and, more often, computer file or files containing such a difference, or diff files. The patch is typically a update meant to fix technical glitches like bugs or improving the usability or the performance of the previous version of an application.

The original patch program was written by Larry Wall, who is also an author of a popular programming language Perl. The program is capable of applying various formats of diffs and has become quite popular among developers who frequently exchange a small change in programs with fellow programmers.