GREX - Version 1.11 With GREX is it possible to split large files and easily put them back together again in the program or with a bat file that is created during the split process. It's also possible to rename files in a directory, it's possible to change the case, the extension, append, replace, remove characters. And much much more. There is also an option that lets yo cleanup directories, simply specify the filetypes, then the directory to cleanup and press the button, just as simple as that.