REM file: Newdir.bas - Public Domain DOS Utility
REM Version 1.0a created 05/22/1995
REM Version 1.1a created 03/26/2001
REM Version 1.2a created 12/10/2005

' default integer variables
DEFINT A-Z
REM $DYNAMIC

' define boolean values
CONST True = -1
CONST False = NOT True
CONST TrueD = -1#
CONST FalseD = NOT TrueD
CONST NUL = ""

' define color values
CONST Black = 0
CONST Cyan = 11
CONST Green = 10
CONST Plain = 7
CONST Red = 12
CONST White = 15
CONST Yellow = 14

' get include files
REM $INCLUDE: 'qbx.bi'
REM $INCLUDE: 'dta.bi'

' declare functions
DECLARE FUNCTION ParseLine (S$)
DECLARE FUNCTION BreakIS()
DECLARE FUNCTION ClearBreak()
DECLARE FUNCTION KeyIS()

' initialize filename buffer
DIM ASCIIZ AS STRING * 260, DTAfile AS DTAtype

' initialize drive variables
COMMON SHARED Drive.Number AS INTEGER, Current.Drive AS INTEGER

' declare program dta
DIM BASIC.DTA.SEG AS INTEGER, BASIC.DTA.OFF AS INTEGER

' declare registers
COMMON SHARED InregsX AS RegTypeX, OutregsX AS RegTypeX
COMMON SHARED InregsX2 AS RegtypeX, InregsX3 AS RegtypeX

' declare work variables
COMMON SHARED Continuous.Display AS INTEGER, Display.Errors AS INTEGER
COMMON SHARED Windows.Detected AS INTEGER

' declare command line work variables
COMMON SHARED Command.Line AS STRING, Command.Line.Redirect AS STRING
COMMON SHARED Command.Work AS STRING, Control.Break AS INTEGER
COMMON SHARED Last.Switch AS INTEGER, Display.Drive AS INTEGER
COMMON SHARED Display.Path AS INTEGER, Pipe.Buffer AS STRING * 1
COMMON SHARED Redirected.Input AS INTEGER

' declare external procedures
DECLARE SUB SetInt
DECLARE SUB RestInt

' backwards compatible for bc 7.1
REM $INCLUDE: 'bc7.inc'

' increase stack size
STACK STACK

' install new interrupt service routine
CALL SetInt

' declare standard error trap
ON ERROR GOTO Error.Routine

' command line parser
FUNCTION ParseLine (X$)
 Imbedded = INSTR(Command.Line, LCASE$(X$))
 IF Imbedded THEN
    Command.Line = LEFT$(Command.Line, Imbedded - 1) + MID$(Command.Line, Imbedded + LEN(X$))
    Last.Switch = Imbedded - 1
    ParseLine = True
 ELSE
    Imbedded = INSTR(Command.Line, UCASE$(X$))
    IF Imbedded THEN
       Command.Line = LEFT$(Command.Line, Imbedded - 1) + MID$(Command.Line, Imbedded + LEN(X$))
       Last.Switch = Imbedded - 1
       ParseLine = True
    ELSE
       ParseLine = False
    END IF
 END IF
END FUNCTION 

' store basic dta
InregsX.AX = &H2F00
CALL InterruptX(&H21, InregsX, OutregsX)
BASIC.DTA.SEG = OutregsX.ES
BASIC.DTA.OFF = OutregsX.BX

' get current drive
InregsX.AX = &H1900
CALL InterruptX(&H21, InregsX, OutregsX)
Current.Drive = OutregsX.AX AND &HFF

' check windows
Windows.Detected = True
If Load.Windows = False Then
   InregsX.AX = &H160A
   CALL InterruptX(&H2F, InregsX, OutregsX)
   IF OutregsX.AX > 0 THEN
      InregsX.AX = &H4A33
      CALL InterruptX(&H2F, InregsX, OutregsX)
      IF OutregsX.AX = 0 THEN
         Windows.Detected = 0 ' DOS 7.00
      END IF
   END IF
END IF
IF INSTR(COMMAND$, "/_") THEN
   Windows.Detected = True
END IF

' check command line
SELECT CASE COMMAND$
CASE "/?"
   GOTO Boot.Usage
END SELECT

' read command line from PSP
Command.line = NUL
InregsX.AX = &H6200
CALL InterruptX(&H21, InregsX, OutregsX)
PSPsegment = OutregsX.BX
PSPoffset = 128
DEF SEG = PSPsegment
FOR Count = 1 TO 127
   Command.Char = PEEK(PSPoffset + Count)
   SELECT CASE Command.Char
   CASE 0, 10, 13
      EXIT FOR
   CASE ELSE
      Command.line = Command.line + CHR$(Command.Char)
   END SELECT
NEXT
DEF SEG
IF Command.Line = NUL THEN
   Command.Line = ENVIRON$("NEWDIR")
END IF
Command.Line = RTRIM$(Command.Line)

' get switches from command line
Continuous.Display = ParseLine ("/C")
Display.Drive = ParseLine("/D")
Display.Path = ParseLine("/V")
Display.Errors = ParseLine ("/Z")
Control.Break = ParseLine ("/~")
Var = ParseLine("/_")

' recheck command line
IF INSTR(Command.Line, "/") THEN
   GOTO Boot.Error
END IF
Command.Line = RTRIM$(Command.Line)
IF Last.Switch THEN
   IF LEN(Command.Line) > Last.Switch THEN
      GOTO Boot.Error
   END IF
END IF

' remove blanks from command line
Command.Line = RTRIM$(Command.Line)
Command.Line = LTRIM$(Command.Line)
Command.Line.Redirect = Command.Line

' check break flag override
IF Control.Break THEN
   Var = ClearBreak
END IF

' search through all input filenames
Redirected.Input = False

' check pipe length
InregsX.AX = &H4202 ' eof
InregsX.BX = 0 ' stdin
InregsX.CX = 0
InregsX.DX = 0
Call InterruptX(&H21, InregsX, OutregsX)
If OutregsX.AX > 0 Then
   Pipe.Redirect = True
   InregsX.AX = &H4200
   InregsX.BX = 0 ' stdin
   InregsX.CX = 0
   InregsX.DX = 0
   Call InterruptX(&H21, InregsX, OutregsX)
Endif
If Pipe.Redirect = False Then
   DEF SEG = &H40
   X = PEEK(&H71)
   DEF SEG
   IF X = 64 THEN
      DEF SEG = &H40
      POKE &H71, 0
      DEF SEG
   END IF
Endif
DO
   ' check control break
   IF BreakIS THEN
      EXIT DO
   END IF

   ' get standard input
   Standard.Input$ = NUL

   If Pipe.Redirect Then
      DO
         ' read from device
         InregsX.AX = &H3F00
         InregsX.BX = 0 ' stdin
         InregsX.CX = 1 ' char
         InregsX.DS = VARSEG(Pipe.Buffer)
         InregsX.DX = VARPTR(Pipe.Buffer)
         Call InterruptX(&H21, InregsX, OutregsX)
         If (OutregsX.Flags AND &H1) = &H1 Then
            Exit Do
         Endif
         If (OutregsX.Flags AND &H1) = &H0 Then
            If OutregsX.AX = 0 Then
               Exit Do
            Endif

            ' store input
            Redirected.Input = True

            ' store character
            Char$ = Pipe.Buffer

            ' check input character
            SELECT CASE ASC(Char$)
            CASE 10, 26
            CASE 13
               EXIT DO
            CASE ELSE
               Standard.Input$ = Standard.Input$ + Char$
            END SELECT
         END IF
      LOOP
   END IF

   ' clear break flag
   IF Redirected.Input = False THEN
      IF Cleared = False THEN
         Cleared = True
         Var = ClearBreak
      END IF
   END IF

   ' check control break
   IF BreakIS THEN
      EXIT DO
   END IF

   ' check nul filename input
   IF Redirected.Input = False THEN
      IF Standard.Input$ = NUL THEN
         CALL RestInt ' restore Control-Break
         X$ = Inkey$ ' quits here
         CALL SetInt ' reset Control-Break
         IF X$ = CHR$(0) + CHR$(0) THEN
            EXIT DO
         END IF
      END IF
   END IF

   ' check standard input
   IF Redirected.Input THEN
      IF Standard.Input$ = NUL THEN
	 EXIT DO
      END IF
   END IF

   ' display header
   GOSUB Header

   ' store entire command
   Command.Work = Command.Line.Redirect

   ' filename processing loop
   DO

      ' store redirected input
      Standard.Input$ = RTRIM$(Standard.Input$)
      Standard.Input$ = LTRIM$(Standard.Input$)
      IF LEFT$(Standard.Input$, 1) = CHR$(34) THEN
         Standard.Input$ = MID$(Standard.Input$, 2)
      END IF
      IF RIGHT$(Standard.Input$, 1) = CHR$(34) THEN
         Standard.Input$ = LEFT$(Standard.Input$, LEN(Standard.Input$) - 1)
      END IF

      ' store entire command
      IF LEFT$(Command.Line, 1) = CHR$(34) THEN
         Imbedded = INSTR(2, Command.Line, CHR$(34))
         IF Imbedded THEN
            Command.Work = Standard.Input$ + MID$(Command.Line, 2, Imbedded - 2)
            Command.Line = MID$(Command.Line, Imbedded + 1)
         ELSE
            Command.Work = Standard.Input$ + Command.Line
            Command.Line = NUL
         END IF
      ELSE
         Imbedded = INSTR(Command.Line, " ")
         IF Imbedded THEN
            Command.Work = Standard.Input$ + LEFT$(Command.Line, Imbedded - 1)
            Command.Line = MID$(Command.Line, Imbedded + 1)
         ELSE
            Command.Work = Standard.Input$ + Command.Line
            Command.Line = NUL
         END IF
      END IF
      Command.Line = LTRIM$(Command.Line)
      Command.Line = RTRIM$(Command.Line)

      ' store current drive
      IF MID$(Command.Work, 2, 1) = ":" THEN
         Drive.Number = ASC(UCASE$(LEFT$(Command.Work, 1))) - 65
         Command.Work = MID$(Command.Work, 3)
      ELSE
	 Drive.Number = Current.Drive
      END IF

      ' check windows dos
      IF Windows.Detected THEN
         ' get current directory
         InregsX.AX = &H7147
         InregsX.DX = Drive.Number + 1
         InregsX.DS = VARSEG(ASCIIZ)
         InregsX.SI = VARPTR(ASCIIZ)
         CALL InterruptX(&H21, InregsX, OutregsX)
      ELSE
         ' get current directory
         InregsX.AX = &H4700
         InregsX.DX = Drive.Number + 1
         InregsX.DS = VARSEG(ASCIIZ)
         InregsX.SI = VARPTR(ASCIIZ)
         CALL InterruptX(&H21, InregsX, OutregsX)
      END IF

      ' display any errors
      CALL DisplayError ("Error accessing drive.")

      ' check carry flag error
      IF (OutregsX.Flags AND &H1) = &H0 THEN

         ' store current directory
         Directory.Search$ = "\" + LEFT$(ASCIIZ, INSTR(ASCIIZ, CHR$(0)) - 1)
         Imbedded1 = INSTR(Command.Work, "\")
         Imbedded2 = Imbedded1
         WHILE Imbedded1
            Imbedded2 = Imbedded1
            Imbedded1 = INSTR(Imbedded1 + 1, Command.Work, "\")
         WEND
         IF Imbedded2 THEN
            Directory.Search$ = LEFT$(Command.Work, Imbedded2)
            Command.Work = MID$(Command.Work, Imbedded2 + 1)
         END IF
         IF RIGHT$(Directory.Search$, 1) <> "\" THEN
            Directory.Search$ = Directory.Search$ + "\"
         END IF
   
         ' get filename spec
         Filename.Search$ = Command.Work
         IF Filename.Search$ = NUL THEN
            IF RIGHT$(Directory.Search$, 1) = "\" THEN
               IF LEN(Directory.Search$) > 1 THEN
                  Directory.Search$ = LEFT$(Directory.Search$, LEN(Directory.Search$) - 1)
               END IF
            END IF
         ELSE
            Directory.Search$ = Directory.Search$ + Filename.Search$
         END IF
         Command.Work = NUL

         ' change to drive
         InregsX.AX = &HE00
         InregsX.DX = Drive.Number
         CALL InterruptX(&H21, InregsX, OutregsX)
   
         ' make directory filename
         ASCIIZ = Directory.Search$ + CHR$(0)

         ' check windows dos
         IF Windows.Detected THEN
            ' change to directory
            InregsX.AX = &H713B
            InregsX.DS = VARSEG(ASCIIZ)
            InregsX.DX = VARPTR(ASCIIZ)
            CALL InterruptX(&H21, InregsX, OutregsX)
         ELSE
            ' change to directory
            InregsX.AX = &H3B00
            InregsX.DS = VARSEG(ASCIIZ)
            InregsX.DX = VARPTR(ASCIIZ)
            CALL InterruptX(&H21, InregsX, OutregsX)
         END IF

         ' display any errors
         CALL DisplayError ("Error changing directory.")

         ' check carry flag error
         IF (OutregsX.Flags AND &H1) = &H0 THEN

            ' display drive letter
            IF Display.Drive THEN
               COLOR Yellow, Black
               PRINT CHR$(Drive.Number + 65); ":";
            END IF

            ' display pathname
            IF Display.Path = False THEN
               COLOR Yellow, Black
               Outpt$ = Directory.Search$
               IF Windows.Detected = False THEN
                  Outpt$ = UCASE$(Outpt$)
               END IF
               PRINT Outpt$
            END IF
            IF Display.Drive AND Display.Path THEN
               PRINT
            END IF
         END IF
      END IF

      ' check search filename
      IF Command.Line = NUL THEN
	 EXIT DO
      END IF
   LOOP

   ' check search filename
   IF Standard.Input$ = NUL THEN
      EXIT DO
   END IF
LOOP

End.Newdir:

' restore basic dta
InregsX.AX = &H1A00
InregsX.DS = BASIC.DTA.SEG
InregsX.DX = BASIC.DTA.OFF
CALL InterruptX(&H21, InregsX, OutregsX)

' restore current drive
InregsX.AX = &HE00
InregsX.DX = Current.Drive
CALL InterruptX(&H21, InregsX, OutregsX)

' display end program
IF Continuous.Display = False THEN
   Prompt$ = "Press <enter> to exit to DOS:"
   CALL MorePrompt(Prompt$, CHR$(13), Outpt$)
END IF

' restore key trapping
CALL RestInt

COLOR Plain, Black
END

' display program usage
Boot.Usage:
 ' restore key trapping
 CALL RestInt
 Var$=Inkey$
 ' make header
 COLOR White, Black
 PRINT "Newdir v1.2a: Directory change utility; "
 COLOR Yellow, Black
 PRINT "Usage:"
 PRINT "   Newdir [d:][path] [/cdvz]"
 PRINT "Where:"
 PRINT "   /c  continuous display"
 PRINT "   /d  display drive letter"
 PRINT "   /v  don't display pathname"
 PRINT "   /z  suppress error messages"
 COLOR Plain, Black
 END

Boot.Error:
 CALL RestInt
 Var$=Inkey$
 COLOR White, Black
 PRINT "Command line error. Type Makdir /? for help."
 COLOR Plain, Black
 END

' make header
Header:
 IF Header.Flag THEN
    RETURN
 END IF
 Header.Flag = True
 IF Continuous.Display = False THEN
    COLOR White, Black
    PRINT "Newdir v1.2a: Directory change utility; "
 END IF
 RETURN

' critical error trap
Error.Routine:
 Data.Error = ERR
 IF Display.Errors THEN
    Error.Level = True
    OutregsX.Flags = &H1
    RESUME NEXT
 END IF
 SELECT CASE Data.Error
 CASE 53
    Temp.Outpt$ = "File not found."
 CASE 61
    Temp.Outpt$ = "Disk full."
 CASE 70
    Temp.Outpt$ = "Permission denied."
 CASE 71
    Temp.Outpt$ = "Disk not ready."
 CASE ELSE
    Temp.Outpt$ = "Untrapped error" + STR$(Data.Error) + "."
 END SELECT
 COLOR Green, Black
 PRINT Temp.Outpt$
 Prompt$ = "Press R to retry, Q to quit, C to continue:"
 CALL MorePrompt(Prompt$, "rqc", Outpt$)
 IF BreakIS THEN
    Outpt$ = "q"
 END IF
 SELECT CASE Outpt$
 CASE "r"
    RESUME
 CASE "q"
    Error.Level = True
    RESUME End.Newdir
 CASE "c"
    OutregsX.Flags = &H1
    RESUME NEXT
 END SELECT
 COLOR Plain, Black
 ' restore key trapping
 CALL RestInt
 END 0

SUB MorePrompt (Input.String$, Input.Mask$, Output.String$)
 COLOR White, Black
 PRINT Input.String$ + " ";
 Input.Char$ = NUL
 DO
    LOCATE , , 1
    InregsX2 = InregsX
    DO
       IF BreakIS THEN
          EXIT DO
       END IF
       IF KeyIS THEN
          IF OutregsX.AX <> 0 THEN
             InregsX.AX = &H0000
             CALL InterruptX(&H16, InregsX, OutregsX)
             Input.Char$=CHR$(OutregsX.AX AND &HFF)
             EXIT DO
          END IF
       END IF
       ' release time slice.
       InregsX.AX = &H1680
       InregsX.BX = &H0000
       CALL InterruptX(&H2F, InregsX, OutregsX)
    LOOP
    InregsX = InregsX2
    IF BreakIS THEN
       EXIT DO
    END IF
    IF LEN(Input.Char$) THEN
       Input.Char$ = LCASE$(Input.Char$)
       IF INSTR(Input.Mask$, Input.Char$) THEN
	  PRINT Input.Char$
	  Output.String$ = Input.Char$
	  EXIT DO
       END IF
    END IF
 LOOP
END SUB

' clears Control-Break flag
FUNCTION ClearBreak
 DEF SEG = &H40
 POKE &H71, &H0
 DEF SEG
 ClearBreak = True
END FUNCTION

' checks Control-Break flag
FUNCTION BreakIS
 STATIC Var AS INTEGER
 IF Redirected.Input THEN
    DEF SEG = &H40
    X = PEEK(&H71)
    DEF SEG
    IF X = 64 THEN
       Var = True
    END IF
 END IF
 IF KeyIS THEN
    IF OutregsX.AX = 0 THEN
       Var = True
       DEF SEG = &H40
       POKE &H71, 64
       DEF SEG
    END IF
 END IF
 IF Var THEN
    Continuous.Display = True
 END IF
 BreakIS = Var
END FUNCTION

' checks keyboard buffer
FUNCTION KeyIS
 InregsX3 = InregsX
 InregsX.AX = &H0100
 CALL InterruptX(&H16, InregsX, OutregsX)
 InregsX = InregsX3
 IF (OutregsX.Flags AND &H40) = &H40 THEN
    KeyIS = False
 ELSE
    KeyIS = True
 END IF
END FUNCTION

' displays carry flag error
SUB DisplayError (Temp$)
 ' check carry flag error
 IF (OutregsX.Flags AND &H1) = &H1 THEN
    ' check display errors flag
    IF Display.Errors = False THEN
       ' display error
       COLOR Red, Black
       PRINT Temp$
    END IF
 END IF
END SUB
