DOS SHELL

 BBS: Inland Empire Archive
Date: 02-22-93 (23:04)             Number: 378
From: WALT MAYO                    Refer#: NONE
  To: ALL                           Recvd: NO  
Subj: DOS SHELL                      Conf: (2) Quik_Bas

I don't know who wrote this, but I found it in a snippet
file from this echo. It's about 2 years old. Anyone who
wants to put a SHELL TO DOS feature in their program will
like this one. If DOES require modification if you use the
standard QB include file. Get rid of the RegType2
definition and the DECLARE for InteruptX.

'=====================================================================
'Sample program to demonstrate DoShell SUBroutine, which uses
'CALL Interrupt from QB.LIB (QB.QLB).
'=====================================================================
     DEFINT A-Z

     TYPE RegType2
          AX    AS INTEGER
          BX    AS INTEGER
          CX    AS INTEGER
          DX    AS INTEGER
          BP    AS INTEGER
          SI    AS INTEGER
          DI    AS INTEGER
          Flags AS INTEGER
          DS AS INTEGER
          ES AS INTEGER
     END TYPE

     'You must link with QB.LIB (QB.QLB) to use Interrupt functions

     DECLARE SUB InterruptX (Intr%, InReg AS RegType2, OutReg AS RegType2)
     DECLARE SUB DoShell (Before$, Args$, After$)

     DoShell "Type EXIT to return", "", "Welcome back"   'Just to test it
     END

'=====================================================================
'SUB DoShell(Before$,Args$,After$)
'Purpose: Use this routine rather than 'SHELL' and the original
'         drive & directory will be restored when 'EXIT'ing the shell.
'         Before$ = A reminder message to the user.  Usually it will be
'                   something like "Type EXIT to return"
'         After$ = A string message to the user upon reentry into the
'                   calling program.
'         Args$ = Will be the null string "" for a plain vanilla SHELL.
'                 The SUB calls 'SHELL' as 'SHELL Args$'
'======================================================================
     SUB DoShell (Before$, Args$, After$) 'Declare some stuff to use

     DIM InReg AS RegType2
     DIM OutReg AS RegType2
     DIM CurrentDrive AS INTEGER
     DIM CurrentDir AS STRING * 64

     'Get current disk drive

     InReg.AX = &H19 * 256
     InterruptX &H21, InReg, OutReg
     CurrentDrive = OutReg.AX MOD 256

     'Get current directory

     InReg.AX = &H47 * 256
     InReg.DX = CurrentDrive + 1  'Note adding one to drive for this, or
                                  'could use 0 for default drive
     InReg.DS = VARSEG(CurrentDir)
     InReg.SI = VARPTR(CurrentDir)
     InterruptX &H21, InReg, OutReg

     'Do the shell
     IF Before$ <> "" THEN CLS : PRINT Before$  'Optional
     SHELL Args$
     IF After$ <> "" THEN CLS : PRINT After$    'Optional

     'Change to old disk drive
     InReg.AX = &HE * 256
     InReg.DX = CurrentDrive
     InterruptX &H21, InReg, OutReg
          '(InReg.AX MOD 256 is the # of logical drives in the
          'system if anyone is interested)

     'Change to old subdirectory (Could use Int &H21 func &H3B instead)
     ToDir$ = CHR$(ASC("A") + CurrentDrive) + ":\" +
LEFT$(CurrentDir, INSTR(CurrentDir, CHR$(0)))
     CHDIR ToDir$

     END SUB

   -----------------------> \\/alt

--- GoldED 2.40
 * Origin: Periscope! Home of the OPTOMETRY Echo! (1:3627/101)