The Create TestFile Applet function makes it easy to provide a simple way for a user to test all of the files on a CD or DVD. This function creates a digest file much like the Create Digest function, but goes one step further: it also writes a small (less than 400K) “TestFiles.exe” application in the same folder. When the TestFiles applet (applet = tiny application) is executed, it automatically loads the digest file and immediately starts testing the files. The TestFiles application is multi-threaded and responsive to user input even while scanning files on slow media and can be closed instantly if desired. TestFiles shows an easy-to-understand report (such as “Every file is ok”, etc).
The intended usage of this function is for you to build your deployment folder, then run the Create TestFile Applet function on that folder. Two files are added to the folder: TestFiles.exe and checksums.exf. The entire folder can then be burned to CD. From that point, running TestFiles automatically initiates file testing.
The TestFiles.exe application is “read only” in the sense that it cannot generate digest files. It merely reads the digest file created by ExactFile, compares the checksums to the files in the folder and subfolders, and reports.
Specify the folder for in the Folder Path text box, or click the browse button (…). You may also drag-and-drop a folder from Windows Explorer. The digest file will include files in subfolders.
Select the Checksum method for the digest file. MD5 is an excellent choice for validating files on a CD-ROM, but you may choose any checksum method ExactFile supports.
Click Go to begin the process.
TestFiles.exe is multithreaded, but will only run one thread for checksum generation on written CD media. When TestFiles starts, it asks Windows if the base folder is on a “written CD media” drive. If so, it drops to a single hashing thread, otherwise, it runs as many hashing threads as there are CPU cores. Because CD-ROM media has a very low random access speed, there is no point in testing multiple files concurrently, as it will actually make the process slower. However, the hashing thread is always separate from the main application window thread, so TestFiles is responsive to user input even on a damaged CD-ROM where no files can be read reliably.