Int 21 Fn 3700  - Dos 2+ - "switchar" - Get Switch Character               [D]

   AX = 3700h

Return: AL = status
       00h successful
       DL = current switch character
       FFh unsupported subfunction
Desc:  Determine the character which is used to introduce command switches.
     This setting is ignored by MS-DOS commands in version 4.0 and higher,
     but is honored by many third-party programs and by Novell DOS 7
     external commands
BUG:   Novell DOS 7's COMMAND.COM (prior to Update 15) fails to honor the
     SwitChar setting for internal commands even though COMMAND.COM
     honors it in its own command tail (i.e. COMMAND /?); even in Update
     15, internal commands fail to honor SwitChar for the /? help option

Notes: documented in some OEM versions of some releases of DOS
   supported by OS/2 compatibility box
   always returns AL=00h/DL=2Fh for MS-DOS 5+ and DR DOS 3.41-6.0
   Novell DOS 7 COMMAND.COM indicates switch characters other than '/'
     by changing the first backslash (and only the first one) in the
     path it prints for PROMPT $p with a forward slash

See Also: AX=3701h