Simtel MSDOS 1992 June

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Assembly Source File | 1986-02-08 | 12.6 KB | 463 lines

page 64,132 TITLE ATTRIB - a program to alter file attributes NAME ATTRIB ; ; This program was written by Bob Eager, Herne Bay, England. ; It is placed in the public domain. No part of this program ; may be copied and sold for gain. ; ; 9-Feb-86 Introduced HELP and slightly changed output B.E. ; Eiben at Marlboro ; ; There isn't really much in the way of documentation. ATTRIB ; works like the DOS 3 command of the same name (except that it ; is a lot smaller and also DOES a lot MORE!) ; ; For those unfamiliar with that: ; ATTRIB filename - reports file attributes as single letters ; (H, S, R) ; ATTRIB +x filename - sets the x attribute (H, S or R) ; ATTRIB -x filename - unsets the x attribute (H, S or R) ; ; The filename may be a wildcard. ; ; Inverse attributes are provided as a friendly touch: ; ; Hidden <==> Visible ; System <==> User ; Read <==> Write ; ; So +R is the same as -W, etc. ; ; Enjoy! ; .SALL ; ; Values for exit status: ; 0 - Success ; 1 - Parameter too long ; 2 - Incorrect DOS version ; 3 - File does not exist ; 4 - Invalid attribute letter ; ; Constants ; TAB EQU 09H ; Tabulate LF EQU 0AH ; Linefeed CR EQU 0DH ; Carriage return PTHSEP1 EQU '\' ; Normal path separator PTHSEP2 EQU '/' ; Alternate path separator ; STDOUT EQU 1 ; Standard output handle STDERR EQU 2 ; Standard error handle MAXFNAM EQU 63 ; Maximum length of filename ; ; Macro definitions ; MSG MACRO X,Y ;; define a message MES&X DB Y LMES&X EQU $-MES&X ENDM ; $MSG MACRO X ;; display a message on standard error MOV BX,STDERR ;; file handle MOV DX,OFFSET MES&X ;; location of message MOV CX,LMES&X ;; length of message MOV AH,40H ;; write function INT 21H ENDM ; CSEG SEGMENT ; ORG 100H ; ASSUME CS:CSEG,DS:CSEG,ES:CSEG,SS:CSEG ; MAIN PROC FAR JMP MAIN10 ; SUBTTL Data areas PAGE+ ; ; Storage ; ATT DW ? ; Mask and bits specified by parameter FIRST DB ? ; Used for 'find first' calls PARPTR DW ? ; Pointer to next parameter PSIZE DW ? ; Size of path part of filename DISP DB ?,?,?,' ' ; Attribute display string LDISP EQU $-DISP ; Length of DISP FNAME DB MAXFNAM+1 DUP (?) ; Extra byte for terminator DTA DB 43 DUP (?) ; Alternate disk transfer area ; ; Table of attribute settings ; ; The table ATTC is a list of valid attribute letters ; The table ATTON corresponds one-to-one with ATTC for setting an attribute ; The table ATTOFF corresponds one-to-one with ATTC for clearing an attribute ; ATTON and ATTOFF use the high byte of each entry as a mask to clear ; unwanted bits, and the low byte to indicate bits to be set. ; ATTC DB 'RWHVSU' NATT EQU $-ATTC ATTON DW 0FF01H,0FE00H,0FF02H,0FD00H,0FF04H,0FB00H ATTOFF DW 0FE00H,0FF01H,0FD00H,0FF02H,0FB00H,0FF04H ; CRBUF DB CR,LF CRBUFL EQU 2 ; DW 40 DUP (?) ; Stack STACK LABEL WORD ; ; Messages ; MSG 1,<'Parameter too long',CR,LF> MSG 2,<'Filename too long - '> MSG 3,<'Incorrect DOS version',CR,LF> MSG 4,<'No matching file found for '> MSG 5,<'Invalid attribute letter',CR,LF> MSG 6,<CR,LF,'Usage is ATTRIB [+-][X] file.ext',CR,LF> MSG 7,<'Where + sets, - removes attribute X and',CR,LF> MSG 8,<'X = Read-only, System, Hidden,',CR,LF> MSG 9,<' or Write, User, Visible.',CR,LF> ; SUBTTL Main code PAGE+ ; MAIN10: MOV SP,OFFSET STACK ; set up stack ; MOV AH,30H INT 21H ; get DOS version XCHG AH,AL ; make more useful form CMP AX,0200H ; version 2 at least? JAE MAIN20 ; j if so - OK $MSG 3 ; "Incorrect DOS version" MOV AL,2 ; exit status JMP SHORT MAIN60 ; join common exit code ; MAIN20: MOV DX,OFFSET DTA ; set alternate DTA to avoid... MOV AH,1AH ; ...overwriting parameters INT 21H MOV PARPTR,81H ; start of parameter area CALL GETFLAGS ; get any attribute flags JC MAIN60 ; j if error (unrecognised flag) MOV ATT,AX ; save information for later on MAIN30: CALL GETPAR ; read next parameter item JC MAIN60 ; j if no more parameters JMP MAIN32 MAIN31: CALL GETPAR ; read next parameter item JC MAIN50 ; j if no more parameters MAIN32: MOV BYTE PTR FIRST,0 ; clear 'find first' flag MAIN40: CALL GETNAM ; get next filename JC MAIN31 ; j if no more names CALL DOATTR ; handle attribute JC MAIN50 ; j if error (status in AL) JMP MAIN40 ; see if more to do ; MAIN50: XOR AL,AL ; zero status JMP SHORT MAIN61 ; MAIN60: $MSG 6 ; give help $MSG 7 ; $MSG 8 ; $MSG 9 ; MAIN61: MOV AH,4CH ; exit INT 21H MAIN ENDP ; SUBTTL Get attribute flag from command line PAGE ; ; This routine reads an attribute flag and its sense from the command line. ; Attribute flags start with '+' or '-' and continue with a letter. ; Possible letters are: R - read only ; W - read and write (inverse of read only) ; H - hidden ; V - visible (inverse of hidden) ; S - system ; U - user (inverse of system) ; ; On entry: PARPTR points to the first byte of the parameter string ; ; On exit: PARPTR has been updated past the attribute specification if ; one was found ; ; Return is made with AH containing a mask to remove any unwanted bits, ; and with AL containing any additional bits to be set in the attributes. ; The value AX=0 is returned if no attribute flag was found, and carry is set ; if an unrecognised attribute letter was encountered. ; GETFLAGS PROC NEAR CLD ; autoincrement MOV SI,PARPTR ; point to start of parameter list PUSH SI ; save for possible restoration GETF10: LODSB ; skip leading spaces... CMP AL,' ' JE GETF10 CMP AL,TAB ; ...and tabs JE GETF10 CMP AL,'+' ; valid sense? JE GETF20 ; j if so CMP AL,'-' ; other sense? JE GETF20 ; j if so POP AX ; restore the parameter... MOV PARPTR,AX ; ...pointer XOR AX,AX ; indicate no attribute specified RET ; return with carry clear ; GETF20: POP BX ; lose saved parameter pointer PUSH AX ; save sense LODSB ; get attribute letter CALL UPPER ; convert to upper case MOV BX,OFFSET ATTC ; list of valid letters MOV CX,NATT ; count of valid letters XOR DI,DI ; pointer into letter table GETF30: CMP AL,[BX+DI] ; found the letter? JE GETF40 ; j if so INC DI ; point to next possibility LOOP GETF30 ; keep trying $MSG 5 ; "Invalid attribute letter" POP AX ; lose sense from stack MOV AL,4 ; exit status STC ; indicate error RET ; GETF40: MOV BX,OFFSET ATTON ; assume sense 'on' POP AX ; now check specified sense CMP AL,'-' JNE GETF50 ; j if sense 'on' required MOV BX,OFFSET ATTOFF ; else use different table GETF50: ADD DI,DI ; form word offset MOV AX,[BX+DI] ; get mask and attribute word MOV PARPTR,SI ; update parameter line pointer CLC ; indicate success RET GETFLAGS ENDP ; SUBTTL Get next parameter PAGE ; ; This routine reads the next parameter from the command line, converting ; it to upper case and placing it into the area FNAME. ; Parameters are delimited by spaces, tabs, commas or the end of the line. ; ; On exit: ; Carry is clear if a parameter was found ; Carry is set if the parameter list is exhausted ; GETPAR PROC NEAR CLD ; autoincrement MOV SI,PARPTR ; point to start of possible parameter GETP10: LODSB ; skip leading spaces... CMP AL,' ' JE GETP10 CMP AL,TAB ; ...and tabs JE GETP10 MOV DI,OFFSET FNAME ; area to hold item MOV CX,MAXFNAM ; maximum item size GETP20: CMP AL,CR ; end of list? JNE GETP30 ; j if not DEC SI ; must re-read next time JMP SHORT GETP40 GETP30: CMP AL,' ' ; other terminators... JE GETP40 CMP AL,TAB JE GETP40 CMP AL,',' JE GETP40 ; ...are space, tab and comma CALL UPPER ; convert to upper case STOSB ; store character away LODSB ; get next character LOOP GETP20 ; GETP40: JCXZ GETP60 ; j if too long XOR AL,AL ; add terminator STOSB MOV PARPTR,SI ; save new value CMP CX,MAXFNAM ; null item? JNE GETP50 ; j if not STC ; indicate no more RET ; GETP50: CLC ; indicate item found RET ; GETP60: $MSG 1 ; "Parameter too long" MOV AL,1 ; exit status JMP MAIN60 GETPAR ENDP ; SUBTTL Get next filename PAGE ; ; This routine gets the next filename matching the parameter. ; The filename is left in FNAME. ; ; On exit: ; Carry is clear if a match was found ; Carry is set if no further matches exist ; GETNAM PROC NEAR CLD ; autoincrement CMP FIRST,0 ; first time with this parameter item? JNE GETN60 ; j if not INC FIRST ; mark not first any more ; MOV SI,OFFSET FNAME ; find last separator GETN10: MOV BX,SI ; initial value GETN20: LODSB ; get next byte of name OR AL,AL ; end of name? JZ GETN30 ; j if so CMP AL,PTHSEP1 ; normal separator? JE GETN10 ; j if so, and update pointer CMP AL,PTHSEP2 ; alternate separator? JE GETN10 ; j if so, and update pointer CMP AL,':' ; drive name? JE GETN10 ; j if so; this counts as separator JMP GETN20 ; ; BX now points at first character of last component of filename ; GETN30: SUB BX,OFFSET FNAME ; derive length of path part MOV PSIZE,BX MOV DX,OFFSET FNAME MOV CX,07H ; get read only, system and hidden files too MOV AH,4EH ; find first matching file INT 21H JNC GETN40 ; j if match found $MSG 4 ; "No matching file found for " MOV BX,STDERR CALL PRNAME MOV BX,STDERR CALL CRLF STC ; indicate error RET ; GETN40: MOV SI,OFFSET DTA+30 ; terminal filename MOV DI,OFFSET FNAME ADD DI,PSIZE ; point to filename part of path MOV CX,MAXFNAM GETN50: LODSB STOSB OR AL,AL LOOPNE GETN50 ; copy name and terminator JCXZ GETN70 ; j if name too long CLC RET ; return with carry clear ; GETN60: MOV AH,4FH ; find next matching file INT 21H JNC GETN40 ; j if match found RET ; return with carry still set ; GETN70: $MSG 2 ; "Filename too long - " MOV BX,STDERR CALL PRNAME MOV BX,STDERR CALL CRLF STC ; indicate error RET GETNAM ENDP ; SUBTTL Actual attribute alteration and display code PAGE ; DOATTR PROC NEAR CMP ATT,0 ; just display required? JZ DOA100 ; j if so ; MOV AX,4300H ; first get existing attributes MOV DX,OFFSET FNAME INT 21H ; attribute to CX (just CL really) JC DOA200 ; j if error (should not happen) AND CL,BYTE PTR ATT+1 ; remove unwanted bits OR CL,BYTE PTR ATT ; add new bits MOV AX,4301H ; set attributes now MOV DX,OFFSET FNAME INT 21H JC DOA200 ; j if error (should not happen) RET ; DOA100: MOV AX,4300H ; get attribute MOV DX,OFFSET FNAME INT 21H ; returns attribute in CX JC DOA200 ; j if error (should not happen) ; MOV DI,OFFSET DISP ; point to output area CLD ; autoincrement MOV AH,'_' MOV AL,AH ; assume space initially TEST CL,01H ; read only attribute? JZ DOA110 ; j if not MOV AL,'R' ; else set character DOA110: STOSB ; set up for output MOV AL,AH ; restore space TEST CL,02H ; hidden attribute? JZ DOA120 ; j if not MOV AL,'H' ; else set character DOA120: STOSB ; set up for output MOV AL,AH ; restore space TEST CL,04H ; system attribute? JZ DOA130 ; j if not MOV AL,'S' ; else set character DOA130: STOSB ; set up for output MOV BX,STDOUT ; handle MOV CX,LDISP ; byte count for message MOV DX,OFFSET DISP MOV AH,40H ; write function INT 21H ; JC DOA200 ; j if error MOV BX,STDOUT ; handle CALL PRNAME ; follow up with filename MOV BX,STDOUT CALL CRLF ; finish off line DOA200: RET DOATTR ENDP ; SUBTTL Miscellaneous subroutines PAGE ; ; Routine to convert the letter in AL to upper case. ; UPPER PROC NEAR CMP AL,'a' ; check lower range JB UPP10 ; j if out of range CMP AL,'z' ; check upper range JA UPP10 ; j if out of range SUB AL,'a'-'A' ; do the conversion UPP10: RET UPPER ENDP ; ; Routine to write a carriage return and linefeed to the file specified ; by the handle in BX. ; CRLF PROC NEAR MOV CX,CRBUFL ; byte count MOV DX,OFFSET CRBUF MOV AH,40H ; write function INT 21H RET CRLF ENDP ; ; Routine to output the filename in FNAME to the file specified by the ; handle in BX. ; PRNAME PROC NEAR MOV DI,OFFSET FNAME PUSH DI ; save for later CLD ; autoincrement XOR AL,AL ; search for zero byte MOV CX,0FFFFH ; very long loop! REPNE SCASB MOV CX,DI POP DX ; initial pointer SUB CX,DX ; derive length MOV AH,40H ; write function INT 21H RET PRNAME ENDP ; CSEG ENDS ; END MAIN