Seems to work "OK".... I just tried it using an old Dogecoin wallet.dat using the "bash" shell in Windows 10 Dev mode...
strings wallet.dat | grep purpose
and
strings wallet.dat | grep name
Both returned a list of addresses contained in the wallet.dat ("name" seemed to list more results)... All the addresses were shown in the "correct" format for the wallet type... ie. they all start with a "D"... so I can tell they are "Dogecoin".
Give it a try and see what addresses you can see listed and see what the first letter of the address is... that should help identify which altcoin the wallet belongs to.