Manual:CheckImages.php/en

Details
checkImages.php file is a maintenance script to check images to see if they exist, are readable, etc.

Technical details
These notes based on an examination of  from MediaWiki version 1.19.

When executed, the main loop iterates through the wiki database's table, fetching 1000 rows at a time by default, until all rows are obtained.

Each row specifies an image name, image size, and location of the associated image data.

If the location is filename on a local path, the filename is tested with.

This test does not attempt to read any data from the image files, so it will not detect unreadable blocks in the local file system.

Options/Arguments
This script does not take any argument.