DMCHECK a utility to check the version of DOOM, to check if the installed
version is registered or not, to verify the available free disk space, to
change or display the date/time of a file and to show a prompt while waiting
for a key to be pressed as a responce.
This will be usefull mostly for PWAD authors that want to make sure the user
has the proper DOOM version and that the files haven't been modified.
It works with ERRORLEVEL codes, so can be used in batch files.|