As I recall, so could / would DOS - at the Int21 syscall level.
The SWITCHAR option was present to set a value which COMMAND.COM (and other DOS utils) consulted such that one could make it honour '-' as the flag leader, and then accept '/' at COMMAND.COM (and other DOS utils).
Unfortunately not all third party utils honoured that, and so it usually ended up not being worth flipping it in to Unix compatible mode.
That said, one could take advantage of the recognition of '/' in programs one wrote, e.g. C code (so avoiding "directory\\file.txt").
INT 21h, function 37h could be used to get and set the switch character for MS-DOS, in addition to requiring the use of '/DEV/' for device filenames:
* AL=0, return switch character in DL
* AL=1, set switch character to character in DL
* AL=2, return '/DEV/' setting in DL
* AL=3, DL=0 if '/DEV/' required, DL<>0 if not.
Okay, why do I remember this stuff? I haven't programmed MS-DOS for over 25 years!
The SWITCHAR option was present to set a value which COMMAND.COM (and other DOS utils) consulted such that one could make it honour '-' as the flag leader, and then accept '/' at COMMAND.COM (and other DOS utils).
Unfortunately not all third party utils honoured that, and so it usually ended up not being worth flipping it in to Unix compatible mode.
That said, one could take advantage of the recognition of '/' in programs one wrote, e.g. C code (so avoiding "directory\\file.txt").