tdos.pas

Turbo Pascal 6.0编译器源码

        CMP     AH,':'
        JNE     @@1
        CMP     AL,'a'
        JB      @@2
        CMP     AL,'z'
        JA      @@2
        SUB     AL,20H
        JMP     @@2
@@1:    DEC     SI
        DEC     SI
        MOV     AH,19H
        INT     21H
        ADD     AL,'A'
        MOV     AH,':'
@@2:    STOSW
        CMP     SI,CX
        JE      @@3
        CMP     [SI].Byte,'\'
        JE      @@4
@@3:    SUB     AL,'A'-1
        MOV     DL,AL
        MOV     AL,'\'
        STOSB
        PUSH    SI
        PUSH    DS
        MOV     AH,47H
        MOV     SI,DI
        PUSH    ES
        POP     DS
        INT     21H
        POP     DS
        POP     SI
        JC      @@4
        CMP     ES:[DI].Byte,0
        JE      @@4
        PUSH    CX
        MOV     CX,-1
        XOR     AL,AL
        REPNZ   SCASB
        DEC     DI
        MOV     AL,'\'
        STOSB
        POP     CX
@@4:    SUB     CX,SI
        REP     MOVSB
        XOR     AL,AL
        STOSB
        LEA     DI,ResultC
        MOV     SI,DI
        PUSH    ES
        POP     DS
        MOV     CX,-1
@@5:    LODSB
        OR      AL,AL
        JZ      @@8
        CMP     AL,'\'
        JE      @@8
        CMP     AL,'.'
        JE      @@7
        JCXZ    @@5
        DEC     CX
        CMP     AL,'a'
        JB      @@6
        CMP     AL,'z'
        JA      @@6
        SUB     AL,20H
@@6:    STOSB
        JMP     @@5
@@7:    MOV     CX,3
        JMP     @@6
@@8:    CMP     [DI-2].Word,'.\'
        JNE     @@9
        DEC     DI
        DEC     DI
        JMP     @@11
@@9:    CMP     [DI-2].Word,'..'
        JNE     @@11
        CMP     [DI-3].Byte,'\'
        JNE     @@11
        SUB     DI,3
        CMP     [DI-1].Byte,':'
        JE      @@11
@@10:   DEC     DI
        CMP     [DI].Byte,'\'
        JNE     @@10
@@11:   MOV     CX,8
        OR      AL,AL
        JNZ     @@6
        CMP     [DI-1].Byte,':'
        JNE     @@12
        MOV     AL,'\'
        STOSB
@@12:   LEA     SI,ResultC
        MOV     AX,DI
        SUB     AX,SI
        CMP     AL,79
        JB      @@13
        MOV     AL,79
@@13:   LES     DI,Result
        STOSB
        CBW
        XCHG    AX,CX
        REP     MOVSB
        POP     DS
end;

procedure SMove; near; assembler;
asm
        SUB     DX,BX
        CMP     AX,BX
        JB      @@1
        MOV     AX,BX
@@1:    STOSB
        MOV     CX,AX
        ADD     BX,SI
        REP     MOVSB
        MOV     SI,BX
end;

procedure FSplit(Path: PathStr; var Dir: DirStr; var Name: NameStr;
  var Ext: ExtStr); assembler;
asm
        PUSH    DS
        LDS     SI,Path
        CLD
        LODSB
        MOV     DL,AL
        XOR     DH,DH
        MOV     BX,DX
        OR      BX,BX
        JZ      @@2
@@1:    CMP     [BX+SI-1].Byte,'\'
        JE      @@2
        CMP     [BX+SI-1].Byte,':'
        JE      @@2
        DEC     BX
        JNZ     @@1
@@2:    MOV     AX,67
        LES     DI,Dir
        CALL    SMove
        XOR     BX,BX
        JMP     @@4
@@3:    CMP     [BX+SI].Byte,'.'
        JE      @@5
        INC     BX
@@4:    CMP     BX,DX
        JNE     @@3
@@5:    MOV     AX,8
        LES     DI,Name
        CALL    SMove
        MOV     BX,DX
        MOV     AX,4
        LES     DI,Ext
        CALL    SMove
        POP     DS
end;

function FRename(Path, NewName: PathStr): Integer; assembler;
var
  NewNameC, PathC: array[0..79] of Char;
asm
        PUSH    DS
        LDS     SI,NewName
        LEA     DI,NewNameC
        CALL    Pas2C
        PUSH    DS
        PUSH    DX
        LDS     SI,Path
        LEA     DI,PathC
        CALL    Pas2C
        POP     DI
        POP     ES
        MOV     AH,56H
        INT     21H
        JNC     @@1
        NEG     AX
        JMP     @@2
@@1:    XOR     AX,AX
@@2:    POP     DS
end;

function GetCurDir(Drive: Char): DirStr; assembler;
asm
        MOV     AL,Drive
        OR      AL,AL
        JNZ     @@1
        MOV     AH,19H
        INT     21H
        ADD     AL,'A'
@@1:    MOV     DL,AL
        LES     DI,@Result
        MOV     AH,':'
        CLD
        STOSW
        MOV     AL,'\'
        STOSB
        PUSH    DS
        MOV     AH,47H
        SUB     DL,'A'-1
        MOV     SI,DI
        PUSH    ES
        POP     DS
        INT     21H
        JNC     @@2
        MOV     [SI].Byte,0
@@2:    POP     DS
        LES     DI,@Result
        CALL    C2Pas
end;

function ChDir(Path: PathStr): Integer; assembler;
var
  PathC: array[0..79] of Char;
asm
        PUSH    DS
        LDS     SI,Path
        LEA     DI,PathC
        CALL    Pas2C
        MOV     AH,3BH
        INT     21H
        JC      @@1
        XOR     AX,AX
@@1:    POP     DS
end;

function GetCurDrive: Char; assembler;
asm
        MOV     AH,19H
        INT     21H
        ADD     AL,'A'
end;

procedure SetCurDrive(Drive: Char); assembler;
asm
        MOV     AH,0EH
        MOV     DL,Drive
        SUB     DL,'A'
        INT     21H
end;

function DriveValid(Drive: Char): Boolean; assembler;
asm
        MOV     DL,Drive
        MOV     AH,36H
        SUB     DL,'A'-1
        INT     21H
        INC     AX
        JZ      @@1
        MOV     AL,1
@@1:
end;

procedure UnpackTime(P: Longint; var T: DateTime); assembler;
asm
        LES     DI,T
        CLD
        MOV     AX,P.Word[2]
        MOV     CL,9
        SHR     AX,CL
        ADD     AX,1980
        STOSW
        MOV     AX,P.Word[2]
        MOV     CL,5
        SHR     AX,CL
        AND     AX,0FH
        STOSW
        MOV     AX,P.Word[2]
        AND     AX,1FH
        STOSW
        MOV     AX,P.Word[0]
        MOV     CL,11
        SHR     AX,CL
        STOSW
        MOV     AX,P.Word[0]
        MOV     CL,5
        SHR     AX,CL
        AND     AX,3FH
        STOSW
        MOV     AX,P.Word[0]
        AND     AX,1FH
        SHL     AX,1
        STOSW
end;

function GetDateTime: Longint; assembler;
asm
        MOV     AH,2AH
        INT     21H
        XCHG    AX,CX
        SUB     AX,1980
        MOV     CL,9
        SHL     AX,CL
        XOR     BX,BX
        MOV     BL,DH
        MOV     CL,5
        SHL     BX,CL
        OR      AX,BX
        OR      AL,DL
        PUSH    AX
        MOV     AH,2CH
        INT     21H
        XOR     AX,AX
        MOV     BX,CX
        XCHG    AL,BH
        MOV     CL,11
        SHL     AX,CL
        XOR     BH,BH
        MOV     CL,5
        SHL     BX,CL
        OR      AX,BX
        SHR     DH,1
        OR      AL,DH
        POP     DX
end;

function GetEnv(EnvVar: string): string; assembler;
var
  EnvVarC: array[0..31] of Char;
asm
        PUSH    DS
        CLD
        LDS     SI,EnvVar
        LEA     DI,EnvVarC
        PUSH    SS
        POP     ES
        LODSB
        CMP     AL,31
        JBE     @@1
        MOV     AL,31
@@1:    CBW
        MOV     CX,AX
        INC     AX
        MOV     DX,AX
        JCXZ    @@4
@@2:    LODSB
        CMP     AL,'a'
        JB      @@3
        CMP     AL,'z'
        JA      @@3
        SUB     AL,20H
@@3:    STOSB
        LOOP    @@2
@@4:    MOV     AL,'='
        STOSB
        POP     DS
        PUSH    DS
        MOV     DS,PrefixSeg
        MOV     DS,DS:2CH
        XOR     SI,SI
@@5:    CMP     [SI].Byte,0
        JE      @@7
        LEA     DI,EnvVarC
        MOV     CX,DX
        REPE    CMPSB
        JE      @@7
        DEC     SI
@@6:    LODSB
        OR      AL,AL
        JNZ     @@6
        JMP     @@5
@@7:    MOV     DI,SI
        PUSH    DS
        POP     ES
        XOR     AL,AL
        MOV     CX,256
        REPNZ   SCASB
        NOT     CL
        LES     DI,@Result
        MOV     AL,CL
        STOSB
        REP     MOVSB
        POP     DS
end;

end.