Content handlers and storage: $wgExternalDiffEngine
Name of the external diff engine to use.
Introduced in version:1.6.0 (r12987)
Removed in version:still in use
Allowed values:(string) or false
Default value:false

Details edit

Name of the external diff engine to use, or false to use the internal engine.

The possible values are:

  • false - wikidiff2 if available, PHP implementation else.
  • any other string is treated as a path to external diff executable, which is passed two file-path arguments.

The following values are no longer supported as of MW 1.32:

MediaWiki version:
  • 'wikidiff2' - Wikimedia's fast difference engine implemented as a PHP/HHVM module.

The following values are no longer supported as of MW 1.27:

MediaWiki version:
  • 'wikidiff' and 'wikidiff3' - treated as false for backwards compatibility.

The external engine should return HTML for a table row containing four columns (two 'marker/content' pairs). These can be collapsed into one for diff formats that don't require columns, e.g. <tr><td colspan="4"></td></tr>

This setting replaces $wgUseExternalDiffEngine .

Example edit

To display diffs in the format of the common GNU diff program, it is necessary to wrap that executable in a small script such as the following. This is needed both to get the required HTML wrapper, and also because diff returns non-zero when inputs don't match (which they generally don't for wiki changes).

    echo "<tr><td colspan=4><pre>"
    # @todo This should also escape HTML.
    diff "$1" "$2"
    echo "</pre></td></tr>"
    if [[ $DIFFRET -eq 1 ]]; then
        exit 0
        exit $DIFFRET
  • LocalSettings.php
    $wgDiffEngine = 'external';
    $wgExternalDiffEngine = '/path/to/';

See also edit