If you are talking about true MS-DOS than it is not possible because MS-DOS is not a multi-tasking operating system. When your program runs there will be no other programs running on the computer.
If your computer is running any version of MS-Windows then you will not be running MS-DOS, but just an emulator which is itself just another MS-Windows program.
>>Basically, I need to write another external program that shows me all the files actually open in the system, and what program is accessing them...
As far as I know it is not possible to do that. The number of files that can be open at any one time is somewhere in the thousands under MS-Windows. The old MS-DOS limit of 15 files has been tossed to the wind several years ago.
Ancient Dragon
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