Patch (computing)

( Patch from eng patch =, in the meaning of rectification masculine, rare neuter. ), Also bugfix is a correction delivery of software or data from end-user perspective, in order to close vulnerabilities, fix bugs, or not far retrofit existing functions A patch. Some manufacturers, such as Microsoft Windows, these updates are called Service Pack, if they consist of several combined patches. The term dates back to the time when it was brought about small adjustments to software on punch cards by punching or taped up individual holes.

  • 4.1 crack
  • 4.2 Community Patch


A patch is a fix for the delivery of executable programs or operating systems and can also contain minor feature enhancements.

  • An update ( update ) extends the functionality of existing executable programs, includes some smaller bug fixes.
  • A bug fix corrects errors in the program source code, which otherwise could cause malfunctions.
  • A hotfix is ​​a particularly important, urgent fix for executable programs or operating systems, but contains no new features.

Objectives for patches

Patch for binaries

A patch for a binary generally replaces one or more files with a new version. Patches for binaries are usually published by manufacturers of proprietary software for their own programs. Are widespread patches for binaries also under software pirates. Here is a copy protection is bypassed with a patch mostly. Even in the computer game scene patches are distributed to modify games.

For applications or operating systems and updates via the Internet are frequently offered, which can be quite easily downloaded and played mostly.

At the time of the operating system CP / M screen and printer control were not yet part of the operating system itself, the adaptation, in the form of escape sequences or small machine programs, had so far in the code of the user program be made of this already foresaw Reserved patch areas. Examples include WordStar, dBase and SuperCalc. The patch is usually performed using a debugger.

Patch for source code

A patch for source code contains only the changed lines in the program code. The most widespread are the formats " context diff" and " unified diff". These patches are used to document the changes and communicate. Patches are an essential part of software development.

Under Unix program code patches are created with the diff program. With the patch program, originally written by Larry Wall, you can automatically upload a patch.

The most popular version control systems use patches to capture changes between file versions.

Patch packages

Often, manufacturers combine multiple patches to a "package " together, which the administrator should install a whole. These packages have different names depending on the manufacturer. Also, a distinction between cumulative (often referred to as cumulative ) packets and non- cumulative packages. When accumulated packets only the latest to be installed because it contains the patches of the previous packages. For non - cumulative packets have to install all the packages in the correct order.


  • Hewlett- Packard: Patchkits for Tru64 UNIX, cumulative
  • Microsoft: Windows service packs, cumulative
  • SAP: Support Packages for SAP R / 3, non- cumulative
  • Sun Microsystems: Patch Cluster for Solaris, cumulative
  • Oracle patch sets, cumulative


Patches are created not only by the original software manufacturer but sometimes also by third parties with different motivation.


→ Main article: Crack (software)

A patch with the purpose of circumvention of copy protection or the like is called " crack". In this case, the binary code of a most commercial program is changed such that it then functions without copy protection. This type of patch is banned in most countries ( see also: Legal position of Software Cracks ).

Community Patch

It can happen that software is no longer maintained by the original manufacturer and legal support, as for example a newer version exists, the usual temporal support frame has expired, or simply the company no longer exists. In these cases, it may happen that the user community trying to keep the maintenance of the software with patching.