On Mon, Oct 19, 2009 at 12:47 PM, Arjun Priyananth priyananth@gmail.com wrote:

Can anyone tell me what is the tool which wikipedia uses for file compare. (in the wikipedia website it compares two history) what is that tool please

It's a PHP difference engine that's part of MediaWiki:

http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/diff/

There's also a C++ version implementing the same algorithm, which is available as a PHP extension and can be used to drastically reduce CPU usage:

http://svn.wikimedia.org/viewvc/mediawiki/trunk/extensions/wikidiff2/

On Mon, Oct 19, 2009 at 1:45 PM, Roan Kattouw roan.kattouw@gmail.com wrote:

It's the standard GNU diff utility, which is available on most Linux/UNIX systems.

Um, no? If we used that, we'd fail on every Windows system, and every Unix system with exec() disabled. Plus, that's a line-level diff, not word-level -- you'd have to use wdiff or such. For undoing, AFAIK we do rely on diff3, and I suspect undoing just always fails on Windows (although I might be wrong, never actually tried).

Arjun Priyananth wrote:

Hi, Can anyone tell me what is the tool which wikipedia uses for file compare. (in the wikipedia website it compares two history) what is that tool please

MediaWiki can use the DifferenceEngine written in php at includes/diff, or the (faster) wikidiff2 php extension.