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Simtel MSDOS - Coast to Coast
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XDEL.ASM
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Assembly Source File
|
1987-12-13
|
17KB
|
363 lines
TITLE XDEL.ASM SCANS CURRENT DIRECTORY ALLOWING FILE DELETION.
; COMMAND LINE SPECIFIES FILE MATCHING MASK
;
DOS EQU 21H ;DOS FUNC INTERRUPT
VIDEO EQU 10H ;BIOS VIDEO INTERRUPT
CSEG SEGMENT
ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG
ORG 80H
PARM LABEL BYTE ;UNFORMATTED AREA OF PSP
ORG 9EH
FNAME LABEL BYTE ;FILE NAME RETURNED IN DTA
; WITHIN PSP BY 4EH CALL
ORG 100H
ENTRY: JMP BEGIN ;SKIP OVER DATA
DB "Copyright 1986 Ziff-Davis Publishing Co.",1Ah
APAGE DB 0 ;CURRENT VIDEO PAGE
db 'ATTR=' ;PATCH POINT TO PRESET
ATTR DB 0 ; SCREEN ATTRIBUTE
COUNT DB 0 ;COUNT FILE NAMES
DELIM DB 9,' ,;=' ;COMMAND LINE DELIMITERS
DRIVE_NO DB ? ;DISK DRIVE (0=A, ETC)
DRIVE_SPEC DB 3 DUP(0) ;DRIVE LETTER & ":"
PATH_SPEC DB '\',65 DUP(0),0 ;CURRENT DIRECTORY
; FILE NAME MASK
DELETE_PATH DB 14 DUP(0),0 ;NAME OF FILE TO DELETE
MATCH_PATH DB 'A:*.*',9 DUP(0),0 ;FILE MATCH STRING
INSTR DB 13,10,10,'Home - first file match ',9,9,9
DB 'PgDn - next file match ',13,10
DB 'F1 - delete last file shown',9,9,9
DB 'ESC - back to DOS',13,10
DB 80 DUP(205),13,0
HDR DB 9,9,9,' DIRECTORY PURGE UTILITY',13,10
DB 'Current Directory :',13,10,0
PATH_MSG DB 16,' ',0 ;RIGHT ARROW
NOT_FOUND DB 13,10,'File not found',0
BAD_SPEC DB 13,10,'Invalid drive / file specification',13,10
DB 'Change directory before using XDEL',0
SPEC_ERROR:
MOV DX,OFFSET BAD_SPEC ;ERROR MSG
CALL PRT_ASCIIZ ;PRINT ERROR
INT 20H ;RETURN TO DOS
BEGIN: MOV AH,8 ;GET CHAR/ATTR AT CURSOR POS
INT VIDEO ;BIOS CALL
MOV APAGE,BH ;BH = ACTIVE PAGE
CMP ATTR,0 ;ATTRIBUTE PRESET?
JNE SCAN_CMD ;YES, USE SPECIFIED ATTR
MOV ATTR,AH ;NO, SAVE CURRENT ATTR
;
;SEARCH UNFORMATTED AREA OF PSP FOR FILE NAME SPECIFICATION
;TO USE IN FILE MATCH COMPARISON
;
SCAN_CMD:
CLD ;SET DIRECTION FLAG
MOV SI,1 + OFFSET PARM ;UNFORMATTED PSP AREA
MOV DI,OFFSET DRIVE_SPEC ;DRIVE SPEC AREA
SKIP_DELIM:
CALL PARM_SCAN ;GET NEXT PARM BYTE
JE SKIP_DELIM ;SKIP OVER LEADING DELIMS
DEC SI ;POINT TO 1ST BYTE OF SPEC
CMP AL,13 ;CARRIAGE RETURN ?
JZ GET_DRIVE ;YES, NO PARM SPECIFIED
CMP BYTE PTR [SI + 1],':' ;DRIVE SPEC PRESENT?
JNZ GET_DRIVE ;NO, GET DEFAULT DRIVE
LODSW ;GET DRIVE AND ":"
AND AL,0DFH ;CAPITALIZE DRIVE LETTER
JMP STORE_DRIVE ;SKIP DEFAULT DRIVE CHECK
GET_DRIVE:
MOV AH,019H ;GET CURRENT DRIVE (0=A,ETC)
INT DOS ; THRU DOS CALL
ADD AL,'A' ;CHANGE TO LETTER
MOV AH,':' ;DRIVE SPEC SEPARATOR
STORE_DRIVE:
CMP AL,'A' ;VALID RANGE OF DRIVES
JB SPEC_ERROR ; INVALID DRIVE
CMP AL,'Z'
JA SPEC_ERROR
STOSW ;SAVE DRIVE SPEC AND ":"
MOV DI,OFFSET DELETE_PATH ;DELETE RTN PATH
STOSW ;LOAD DRIVE
MOV DI,OFFSET MATCH_PATH ;FILE MATCHING PATH
STOSW ;LOAD DRIVE
SUB AL,'A' ;CHG DRIVE TO NUM (0=A, ETC)
MOV DRIVE_NO,AL ;SAVE DRIVE
CMP BYTE PTR [SI],13 ;CARRIAGE RETURN ?
JE GLOBAL_SCAN ;YES, SCAN *.*
MOV CX,12 ;MAX LENGTH FILE SPEC
PARSE:
CALL PARM_SCAN ;GET NEXT PARM BYTE
JE PARSE ;SKIP DELIMS
CMP AL,13 ;CARRIAGE RETURN?
JE END_SPEC ;YES, END OF FILE SPEC
CMP AL,'\' ;PATH SPECIFIED?
JE SPEC_ERROR ;YES, ERROR
STOSB ;MOVE BYTE TO MATCH PATH
DEC CX ;COUNT FILE SPEC LENGTH
JCXZ END_SPEC ;IF CX = 0, STOP BUILD
JMP PARSE
END_SPEC:
MOV BYTE PTR [DI],0 ;TRAILING ZERO
GLOBAL_SCAN:
CALL GET_PATH ;GET PATH FOR DRIVE SPEC
RESTART:
CALL CLR_SCR ;CLEAR SCREEN
MOV DX,OFFSET HDR ;SCREEN TITLE LINE
CALL PRT_ASCIIZ ; AND PRINT
MOV DX,OFFSET PATH_MSG ;DIRECTORY INFO MSG
CALL PRT_ASCIIZ ; AND PRINT
MOV DX,OFFSET DRIVE_SPEC ;DRIVE/PATH/FILE
CALL PRT_ASCIIZ ; AND PRINT
MOV DX,OFFSET PATH_SPEC ;PATH_SPEC
CALL PRT_ASCIIZ ; AND PRINT
MOV DX,OFFSET MATCH_PATH + 2 ;FILE SPEC
CALL PRT_ASCIIZ ; AND PRINT
MOV DX,OFFSET INSTR ;INSTRUCTION LINE
CALL PRT_ASCIIZ ; AND PRINT
MOV COUNT,0 ;INITIALIZE FILE COUNTER
MOV DX,OFFSET MATCH_PATH ;ADDRESS OF SEARCH MATCH
MOV CX,0 ;ATTRIBUTE FOR FILES
MOV AH,04EH ;FIND FIRST MATCH
INT DOS ; THRU DOS FUNC CALL
JC ERROR_RTN ;CARRY SET = ERROR
FILE_LOOP:
MOV DX,OFFSET FNAME ;POINT TO FILE NAME
CALL PRT_ASCIIZ ; AND PRINT
;CX = FILE NAME LENGTH
ADD COUNT,1 ;INCREMENT COUNT
READ_KYBD:
CALL GET_KEY ;GET KEY INSTRUCTION
CMP AL,27 ;ESCAPE KEY?
JE END_PGM ;YES, END PGM
;
; EXTENDED KEY TESTS
;
CMP AL,59 ;FUNC KEY 1?
JE DEL_IT ;YES, DELETE FILE
CMP AL,71 ;HOME KEY?
JE RESTART ;YES, RESTART
CMP AL,81 ;PAGE DOWN?
JE SKIP_IT ;YES, SKIP TO NEXT FILE
JMP READ_KYBD ;NO, IGNORE KEY
DEL_IT:
PUSH CX ;SAVE FILE NAME LENGTH
MOV SI,OFFSET FNAME ;POINT TO FILE NAME
MOV DI,OFFSET DELETE_PATH + 2 ;DELETE PATH FILE SPEC
MOV CX,13 ;BYTES TO MOVE
REP MOVSB ;MOVE FILE NAME
POP CX ;RESTORE FILE NAME LENGTH
CALL DEL_RTN ;DELETE FILE
JC SOUND_ALARM ;CARRY SET - NOT DELETED
MOV DL,017 ;"LEFT POINTER" CHAR
CALL PRT_CHAR ; AND PRINT
INC CX ;INCREMENT STRING COUNT
JMP SKIP_IT ;SKIP TO NEXT FILE
SOUND_ALARM:
MOV DL,07 ;CTRL-G "BEEP" CHAR
CALL PRT_CHAR ; PRINT
JMP READ_KYBD ;READ KEYBOARD AGAIN
SKIP_IT:
CALL SPACE_FILL ;POSITION FOR NEXT NAME
CALL NEXT_FILE ;FIND NEXT FILE MATCH
JC END_PGM ;CARRY SET = NO MORE FILES
CMP COUNT,80 ;80 FILE NAMES DISPLAYED?
JB FILE_LOOP ;NO, SKIP SCROLL
CALL SCROLL_HALF ;SCROLL HALF OF WINDOW
SUB COUNT,40 ;SUBTRACT 40 FROM FILE COUNT
JMP FILE_LOOP ;KEEP GOING
ERROR_RTN:
MOV DX,OFFSET NOT_FOUND ;POINT TO MSG
CALL PRT_ASCIIZ ; AND PRINT
END_PGM:
INT 20H ;RETURN TO DOS
;* * * * * * * * * * S U B R O U T I N E S * * * * * * * * * * * * * * *
;
;GET NEXT PARAMTER BYTE AND COMPARE AGAINST DELIMITER TABLE
; ZERO FLAG INDICATES BYTE IN AL IS DELIMITER
;
PARM_SCAN:
PUSH CX
PUSH DI
LODSB ;GET BYTE AT DS:[SI]
MOV DI,OFFSET DELIM ;POINT TO DELIM STRING
MOV CX,5 ;LENGTH OF DELIM STRING
REPNE SCASB ;SCAN DELIM UNTIL CX=0
; OR AL=DS:[DI]
POP DI
POP CX
RET
;
;GET CURRENT DIRECTORY PATH FOR DRIVE SPECIFIED
;
GET_PATH:
PUSH SI ;SAVE INDEX TO COMMAND LINE
MOV AH,047H ;GET CURRENT DIRECTORY
MOV DL,DRIVE_NO ;GET DRIVE NUMBER (0=A,ETC)
INC DL ;DL = (0=DEFAULT, 1=A, ETC)
MOV SI,OFFSET PATH_SPEC + 1 ;SAVE DIRECTORY TO DS:[SI]
INT DOS ;DOS CALL
SUB AL,AL ;ASCIIZ ZERO BYTE
CMP [SI],AL ;CHECK IF ROOT DIR
JZ ROOT_DIR ;IF SO, SKIP SEARCH
MOV DI,SI ;SCAN PATH FOR HEX 0
MOV CX,64 ;BYTES TO SEARCH
REPNZ SCASB ;DO SEARCH FOR TRAILING ZERO
DEC DI ;DI POINTS TO END ZERO
MOV AL,'\' ;OVERLAY WITH BACK SLASH
STOSB ;APPEND TO PATH
ROOT_DIR:
POP SI ;RESTORE INDEX
RET
;
;FINDS NEXT FILE NAME WHICH MATCHES MASK
;
NEXT_FILE:
PUSH CX
MOV DX,OFFSET MATCH_PATH ;ADDRESS OF MATCH STRING
MOV CX,0 ;ATTRIBUTE FOR FILES
MOV AH,04FH ;FIND NEXT MATCH
INT DOS ;DOS FUNC CALL
POP CX
RET
;
;SPACES OUT FILE NAME TO LENGTH OF 16 BYTES (FIVE NAME PER LINE)
;
SPACE_FILL:
CMP CX,16 ;PRINTED 16 BYTES?
JAE SPC_EXIT ;YES, EXIT
MOV DL,' ' ;NO, PRINT SPACE AFTER NAME
CALL PRT_CHAR ;PRINT CHAR
INC CX ;INCREMENT CX (STRING COUNT)
JMP SPACE_FILL ;KEEP GOING
SPC_EXIT:
RET
;
;PRINTS ASCIIZ STRING POINTED TO BY DS:DX
; CX RETURNS NUMBER OF BYTES PRINTED
;
PRT_ASCIIZ:
PUSH SI
PUSH DX
SUB CX,CX ;INIT BYTE COUNT
MOV SI,DX ;SET SOURCE INDEX
ASC_LOOP:
MOV DL,BYTE PTR [SI] ;POINT TO CHAR IN ASCIIZ
CMP DL,0 ;FOUND TRAILING ZERO?
JZ ASC_EXIT ;YES, EXIT
CALL PRT_CHAR ;NO, PRINT CHAR
INC SI ;POINT TO NEXT BYTE
INC CX ;INCR BYTES PRINTED
JMP ASC_LOOP ;KEEP GOING
ASC_EXIT:
POP DX
POP SI
RET
;
;PRINTS CHARACTER IN DL
;
PRT_CHAR:
PUSH AX
MOV AH,2 ;PRINT CHAR IN DL
INT DOS ;DOS FUNC CALL
POP AX
RET
;
; ACCEPT ONLY ESCAPE, AND ALL EXTENDED KEY CODES
;
GET_KEY:
MOV AH,0 ;GET NEXT KEYBOARD CHAR
INT 16H ;BIOS CALL
CMP AL,27 ;ESCAPE KEY?
JE GET_EXIT ;YES, EXIT
CMP AL,0 ;EXTENDED KEY?
JNZ GET_KEY ;NO, IGNORE
XCHG AH,AL ;SWAP SCAN CODE INTO AL
GET_EXIT:
RET
;
;DELETES FILE NAME IN FIELD "FNAME"
; CARRY FLAG SET - FILE COULD NOT BE DELETED
; CARRY FLAG CLEAR - FILE WAS SUCCESFULLY DELETED
;
DEL_RTN:
MOV DX,OFFSET DELETE_PATH ;POINT TO DELETE PATH
MOV AH,041H ;DELETE FILE FUNC
INT DOS ;DOS CALL
RET
;
;CLEARS ENTIRE SCREEN AND POSITIONS CURSOR IN UPPER LEFT CORNER
;
CLR_SCR:
MOV AH,2 ;SET CURSOR POSITION
MOV BH,APAGE ;SET CURR PAGE
MOV DX,0 ; UPPER LEFT CORNER
INT VIDEO ;BIOS CALL
MOV BH,ATTR ;ATTRIBUTE TO BH
MOV AX,0600H ;SCROLL UP BIOS FUNC
MOV CX,0 ;UPPER LEFT WINDOW CORNER
MOV DX,1850H ;LOWER RIGHT CORNER 24 X 80
INT VIDEO ;BIOS CALL
RET
;
;SCROLLS TOP HALF OF FILE DISPLAY AREA AND POSITIONS CURSOR ON BLANK LINE
;
SCROLL_HALF:
MOV AH,2 ;SET CURSOR POSITION
MOV BH,APAGE ;SET CURR PAGE
MOV DX,0F00H ;PUT CURSOR ON LINE 15
INT VIDEO ;BIOS CALL
MOV BH,ATTR ;ATTRIBUTE TO BH
MOV AX,0608H ;SCROLL UP EIGHT LINES
MOV CX,0700H ;UPPER LEFT CORNER OF WINDOW
MOV DX,1850H ;LOWER RIGHT CORNER 24 X 80
INT VIDEO ;BIOS CALL
RET
CSEG ENDS
END ENTRY
