STRIN.ASM

        procedure   $STD_CON_STRING_INPUT,NEAR   ;System call 10
ASSUME  DS:NOTHING,ES:NOTHING

; Inputs:
;       DS:DX Point to an input buffer
; Function:
;       Fill buffer from console input until CR
; Returns:
;       None

        MOV     AX,SS
        MOV     ES,AX
        MOV     SI,DX
        XOR     CH,CH
        LODSW
        OR      AL,AL
        retz                    ;Buffer is 0 length!!?
        MOV     BL,AH           ;Init template counter
        MOV     BH,CH           ;Init template counter
        CMP     AL,BL
        JBE     NOEDIT          ;If length of buffer inconsistent with contents
        CMP     BYTE PTR [BX+SI],c_CR
        JZ      EDITON          ;If CR correctly placed EDIT is OK
NOEDIT:
        MOV     BL,CH           ;Reset buffer
EDITON:
        MOV     DL,AL
        DEC     DX              ;DL is # of bytes we can put in the buffer
NEWLIN:
        MOV     AL,[CARPOS]
        MOV     [STARTPOS],AL   ;Remember position in raw buffer
        PUSH    SI
        MOV     DI,OFFSET DOSGROUP:INBUF        ;Build the new line here
        MOV     [INSMODE],CH    ;Insert mode off
        MOV     BH,CH           ;No chars from template yet
        MOV     DH,CH           ;No chars to new line yet
        invoke  $STD_CON_INPUT_NO_ECHO          ;Get first char
        CMP     AL,c_LF         ;Linefeed
        JNZ     GOTCH           ;Filter out LF so < works
        entry   GETCH
        invoke  $STD_CON_INPUT_NO_ECHO
GOTCH:
        CMP     AL,"F"-"@"      ;Ignore ^F
        JZ      GETCH
        CMP     AL,[ESCCHAR]
        JZ      ESC
        CMP     AL,c_DEL
        JZ      BACKSPJ
        CMP     AL,c_BS
        JZ      BACKSPJ
        CMP     AL,c_CR
        JZ      ENDLIN
        CMP     AL,c_LF
        JZ      PHYCRLF
        CMP     AL,CANCEL
        JZ      KILNEW
SAVCH:
        CMP     DH,DL
        JAE     BUFFUL          ;No room
        STOSB
        INC     DH              ;Got a char
        invoke  BUFOUT          ;Print control chars nicely
        CMP     BYTE PTR [INSMODE],0
        JNZ     GETCH           ;In insert mode, get more chars
        CMP     BH,BL
        JAE     GETCH           ;We are out of chars in template
        INC     SI              ;Skip to next char in template
        INC     BH
        JMP     SHORT GETCH

BACKSPJ: JMP    SHORT BACKSP

BUFFUL:
        MOV     AL,7            ;Bell
        invoke  OUT
        JMP     SHORT GETCH

ESC:
        transfer    OEMFunctionKey

ENDLIN:
        STOSB                   ;Put the CR in the buffer
        invoke  OUT             ;Echo it
        POP     DI              ;Get start of buffer
        MOV     [DI-1],DH       ;Tell user how many bytes
        INC     DH              ;DH is length including CR
COPYNEW:
        MOV     BP,ES           ;XCHG ES,DS
        MOV     BX,DS
        MOV     ES,BX
        MOV     DS,BP
        MOV     SI,OFFSET DOSGROUP:INBUF
        MOV     CL,DH
        REP     MOVSB           ;Copy final line to user buffer
        return                  ;All done

;Output a CRLF
        entry   CRLF
        MOV     AL,c_CR
        invoke  OUT
        MOV     AL,c_LF
        JMP     OUT

;Output a CRLF which is not terminate buffer
PHYCRLF:
        invoke  CRLF
        JMP     GETCH

;Zap the line without zapping the template
        entry   KILNEW
        MOV     AL,"\"
        invoke  OUT             ;Print the CANCEL indicator
        POP     SI              ;Remember start of edit buffer
PUTNEW:
        invoke  CRLF            ;Go to next line on screen
        MOV     AL,[STARTPOS]
        invoke  TAB             ;Tab over
        JMP     NEWLIN          ;Start over again

;Back up one char
        entry   BACKSP
        OR      DH,DH
        JZ      OLDBAK          ;No chars in line, do nothing to line
        CALL    BACKUP          ;Do the backup
        MOV     AL,ES:[DI]      ;Get the deleted char
        CMP     AL," "
        JAE     OLDBAK          ;Was a normal char
        CMP     AL,c_HT
        JZ      BAKTAB          ;Was a tab, fix up users display
        CALL    BACKMES         ;Was a control char, zap the '^'
OLDBAK:
        CMP     BYTE PTR [INSMODE],0
        JNZ     GETCH1          ;In insert mode, get more chars
        OR      BH,BH
        JZ      GETCH1          ;Not advanced in template, stay where we are
        DEC     BH              ;Go back in template
        DEC     SI
GETCH1:
        JMP     GETCH

BAKTAB:
        PUSH    DI
        DEC     DI              ;Back up one char
        STD                     ;Go backward
        MOV     CL,DH           ;Number of chars currently in line
        MOV     AL," "
        PUSH    BX
        MOV     BL,7            ;Max
        JCXZ    FIGTAB          ;At start, do nothing
FNDPOS:
        SCASB                   ;Look back
        JNA     CHKCNT
        CMP     BYTE PTR ES:[DI+1],9
        JZ      HAVTAB          ;Found a tab
        DEC     BL              ;Back one char if non tab control char
CHKCNT:
        LOOP    FNDPOS
FIGTAB:
        SUB     BL,[STARTPOS]
HAVTAB:
        SUB     BL,DH
        ADD     CL,BL
        AND     CL,7            ;CX has correct number to erase
        CLD                     ;Back to normal
        POP     BX
        POP     DI
        JZ      OLDBAK          ;Nothing to erase
TABBAK:
        invoke  BACKMES
        LOOP    TABBAK          ;Erase correct number of chars
        JMP     SHORT OLDBAK

BACKUP:
        DEC     DH              ;Back up in line
        DEC     DI
BACKMES:
        MOV     AL,c_BS         ;Backspace
        invoke  OUT
        MOV     AL," "          ;Erase
        invoke  OUT
        MOV     AL,c_BS         ;Backspace
        JMP     OUT             ;Done

;User really wants an ESC character in his line
        entry   TwoEsc
        MOV     AL,[ESCCHAR]
        JMP     SAVCH

;Copy the rest of the template
        entry   COPYLIN
        MOV     CL,BL           ;Total size of template
        SUB     CL,BH           ;Minus position in template, is number to move
        JMP     SHORT COPYEACH

        entry   CopyStr
        invoke  FINDOLD         ;Find the char
        JMP     SHORT COPYEACH  ;Copy up to it

;Copy one char from template to line
        entry   COPYONE
        MOV     CL,1
;Copy CX chars from template to line
COPYEACH:
        MOV     BYTE PTR [INSMODE],0    ;All copies turn off insert mode
        CMP     DH,DL
        JZ      GETCH2                  ;At end of line, can't do anything
        CMP     BH,BL
        JZ      GETCH2                  ;At end of template, can't do anything
        LODSB
        STOSB
        invoke  BUFOUT
        INC     BH                      ;Ahead in template
        INC     DH                      ;Ahead in line
        LOOP    COPYEACH
GETCH2:
        JMP     GETCH

;Skip one char in template
        entry   SKIPONE
        CMP     BH,BL
        JZ      GETCH2                  ;At end of template
        INC     BH                      ;Ahead in template
        INC     SI
        JMP     GETCH

        entry   SKIPSTR
        invoke  FINDOLD                 ;Find out how far to go
        ADD     SI,CX                   ;Go there
        ADD     BH,CL
        JMP     GETCH

;Get the next user char, and look ahead in template for a match
;CX indicates how many chars to skip to get there on output
;NOTE: WARNING: If the operation cannot be done, the return
;       address is popped off and a jump to GETCH is taken.
;       Make sure nothing extra on stack when this routine
;       is called!!! (no PUSHes before calling it).
FINDOLD:
        invoke  $STD_CON_INPUT_NO_ECHO
        CMP     AL,[ESCCHAR]            ; did he type a function key?
        JNZ     FindSetup               ; no, set up for scan
        invoke  $STD_CON_INPUT_NO_ECHO  ; eat next char
        JMP     NotFnd                  ; go try again
FindSetup:
        MOV     CL,BL
        SUB     CL,BH           ;CX is number of chars to end of template
        JZ      NOTFND          ;At end of template
        DEC     CX              ;Cannot point past end, limit search
        JZ      NOTFND          ;If only one char in template, forget it
        PUSH    ES
        PUSH    DS
        POP     ES
        PUSH    DI
        MOV     DI,SI           ;Template to ES:DI
        INC     DI
        REPNE   SCASB           ;Look
        POP     DI
        POP     ES
        JNZ     NOTFND          ;Didn't find the char
        NOT     CL              ;Turn how far to go into how far we went
        ADD     CL,BL           ;Add size of template
        SUB     CL,BH           ;Subtract current pos, result distance to skip
        return

NOTFND:
        POP     BP              ;Chuck return address
        JMP     GETCH

        entry   REEDIT
        MOV     AL,"@"          ;Output re-edit character
        invoke  OUT
        POP     DI
        PUSH    DI
        PUSH    ES
        PUSH    DS
        invoke  COPYNEW         ;Copy current line into template
        POP     DS
        POP     ES
        POP     SI
        MOV     BL,DH           ;Size of line is new size template
        JMP     PUTNEW          ;Start over again

        entry   EXITINS
        entry   ENTERINS
        NOT     BYTE PTR [INSMODE]
        JMP     GETCH

;Put a real live ^Z in the buffer (embedded)
        entry   CTRLZ
        MOV     AL,"Z"-"@"
        JMP     SAVCH
$STD_CON_STRING_INPUT   ENDP