mirror of
https://github.com/vxunderground/MalwareSourceCode
synced 2024-06-27 09:28:25 +00:00
216 lines
6.7 KiB
NASM
216 lines
6.7 KiB
NASM
; ATTR.ASM -- File Attribute Utility
|
||
; ==================================
|
||
|
||
CSEG Segment
|
||
Assume CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG
|
||
Org 0080h
|
||
Parameter Label Byte ; Parameter is here
|
||
Org 0100h
|
||
Entry: Jmp Begin ; Entry Point
|
||
|
||
; Most Data (some more at end of program)
|
||
; ---------------------------------------
|
||
|
||
db "ATTR (C) 1986, Ziff-Davis Publishing Co.",1Ah
|
||
db " Programmed by Charles Petzold ",1Ah
|
||
SyntaxMsg db "Syntax: ATTR [+A|-A] [+S|-S] [+H|-H] [+R|-R] "
|
||
db "[drive:][path]filename",13,10
|
||
db " Archive System Hidden Read-Only$"
|
||
DosVersMsg db "ATTR: Needs DOS 2.0 +$"
|
||
FlagErrMsg db "ATTR: Incorrect flag$"
|
||
FileSpecMsg db "ATTR: Incorrect File Spec$"
|
||
Delimiters db 9,' ,;=',13
|
||
FlagList db "ASHR", 20h, 04h, 02h, 01h
|
||
AllFlagList db " $Arc $Dir $$$$$$Sys $Hid $R-O$"
|
||
ChangeFlag db 0
|
||
AndAttrBits db 0
|
||
OrAttrBits db 0
|
||
SearchString dw ?
|
||
AppendFileName dw ?
|
||
|
||
; Check DOS Version
|
||
; -----------------
|
||
|
||
Begin: Mov AH, 30h ; Check for DOS Version
|
||
Int 21h ; through DOS call
|
||
Cmp AL, 2 ; See if it's 2.0 or above
|
||
Jae DosVersOK ; If so, continue
|
||
|
||
Mov DX, Offset DosVersMsg ; Error message
|
||
ErrorExit: Mov AH, 9 ; Print String function call
|
||
Int 21h ; Do it
|
||
Int 20h ; And exit prematurely
|
||
|
||
; Parse Command Line to get file specification
|
||
; --------------------------------------------
|
||
|
||
DosVersOK: Mov SI, 1+Offset Parameter ; Parameter string pointer
|
||
Cld ; Directions forward
|
||
|
||
FlagSearch: Lodsb ; Get Byte
|
||
Mov DI, Offset Delimiters ; Check if delimiter
|
||
Mov CX, 5 ; Five delimiters to check
|
||
Repne Scasb ; Scan the string
|
||
Je FlagSearch ; If delimiter, circle back
|
||
Mov DX, Offset SyntaxMsg ; Possible error msg
|
||
Cmp AL, 13 ; If carriage return, no file
|
||
Je ErrorExit ; so exit with message
|
||
|
||
Mov DI, Offset OrAttrBits ; Pointer to plus flag saver
|
||
Cmp AL, '+' ; See if plus sign
|
||
Je PlusOrMinus ; If so, save the bit
|
||
Mov DI, Offset AndAttrBits ; Pointer to minus flag saver
|
||
Cmp AL, '-' ; See if minus sign
|
||
Jne MustBeFile ; If not, it must be file name
|
||
|
||
PlusOrMinus: Mov [ChangeFlag],-1 ; Set for changing
|
||
Lodsb ; Get the next byte
|
||
And AL, 0DFh ; Capitalize it
|
||
Mov BX, Offset FlagList ; List for scanning
|
||
Mov CX, 4 ; Scan for A, S, H, and R
|
||
|
||
SearchList: Cmp AL, [BX] ; See if a match
|
||
Jz FoundFlag ; If so, proceed to save
|
||
Inc BX ; Kick up pointer
|
||
Loop SearchList ; And loop around for next
|
||
Mov DX, Offset FlagErrMsg ; Otherwise, set message
|
||
Jmp ErrorExit ; And terminate
|
||
|
||
FoundFlag: Mov AL, [BX + 4] ; Get bit mask
|
||
Or [DI], AL ; Turn saved bit on
|
||
Jmp FlagSearch ; And continue looking
|
||
|
||
MustBeFile: Not [AndAttrBits] ; Invert bits for turn off
|
||
Mov [SearchString], SI ; Save file name pointer
|
||
Dec [SearchString] ; Actually one byte lower
|
||
|
||
EndSearch: Lodsb ; Get Byte
|
||
Mov DI, Offset Delimiters ; Check if delimiter
|
||
Mov CX, 6 ; Six delimiters including CR
|
||
Repne Scasb ; Scan the string
|
||
Jne EndSearch ; If not delimiter, keep going
|
||
|
||
; Transfer Search String down at end of program
|
||
; ---------------------------------------------
|
||
|
||
Dec SI ; Points after file spec
|
||
Mov Byte Ptr [SI], 0 ; Make it ASCIIZ string
|
||
Mov CX, SI ; CX points to end
|
||
Mov SI, [SearchString] ; SI points to beginning
|
||
Sub CX, SI ; Now CX is length of it
|
||
Mov DI, Offset PathAndFile ; Destination of string
|
||
Mov [AppendFileName], DI ; Save it here also
|
||
|
||
SearchTrans: Lodsb ; Get byte of search string
|
||
Stosb ; And save it down below
|
||
Cmp AL, ':' ; See if drive marker
|
||
Je PossibleEnd ; If so, take note of it
|
||
Cmp AL, '\' ; See if path separator
|
||
Jne NextCharacter ; If not, skip next code
|
||
|
||
PossibleEnd: Mov [AppendFileName], DI ; This is the new end
|
||
NextCharacter: Loop SearchTrans ; Do it again until done
|
||
|
||
; Find Files from Search String
|
||
; -----------------------------
|
||
|
||
Mov DX, Offset DTABuffer ; Set File Find buffer
|
||
Mov AH, 1Ah ; by calling DOS
|
||
Int 21h
|
||
|
||
Mov DX, [SearchString] ; Search string
|
||
Mov CX, 16h ; Search Everything
|
||
Mov AH, 4Eh ; Find first file
|
||
|
||
FindFile: Int 21h ; Call DOS to find file
|
||
Jnc Continue ; If no error continue
|
||
Cmp AX, 18 ; If not "no more files" error
|
||
Jnz FindError ; print error message
|
||
Jmp NoMoreFiles ; Now get out of the loop
|
||
|
||
FindError: Mov DX, Offset FileSpecMsg ; Error message for file spec
|
||
Jmp ErrorExit ; Exit and print message
|
||
|
||
Continue: Mov SI, 30+Offset DTABuffer ; Points to filename
|
||
Cmp Byte Ptr [SI], '.' ; See if "dot" entry
|
||
Jnz FileIsOK ; If not, continue
|
||
Jmp FindNextFile ; If so, skip it
|
||
|
||
FileIsOK: Mov DI, [AppendFileName] ; Destination of file name
|
||
Mov CX, 14 ; Number of bytes to display
|
||
|
||
TransferName: Lodsb ; Get the byte in file name
|
||
Stosb ; Save it
|
||
Or AL, AL ; See if terminating zero
|
||
Jz PadWithBlanks ; If so, display blanks
|
||
Call DisplayChar ; Display the character
|
||
Loop TransferName ; And loop back around
|
||
|
||
PadWithBlanks: Mov AL, ' ' ; Pad names with blanks
|
||
Call DisplayChar
|
||
Loop PadWithBlanks ; And loop until CX is zero
|
||
|
||
; Change And Display File Attributes
|
||
; ----------------------------------
|
||
|
||
Mov DX, Offset PathAndFile ; Points to ASCIIZ string
|
||
Test [ChangeFlag], -1 ; See if changing attributes
|
||
Jz DisplayIt ; If not, just display them
|
||
|
||
Mov AX, 4300h ; Get file attribute
|
||
Int 21h ; by calling DOS
|
||
And CL, 27h ; Zero out some bits
|
||
And CL, [AndAttrBits] ; Turn off some bits
|
||
Or CL, [OrAttrBits] ; Turn on some bits
|
||
Mov AX, 4301h ; Set file attribute
|
||
Int 21h ; by calling DOS
|
||
|
||
DisplayIt: Mov AX, 4300h ; Get file attribute
|
||
Int 21h ; by calling DOS
|
||
Mov BL, CL ; BL is attributes
|
||
Or BL, 08h ; Turn on Volume bit
|
||
Shl BL, 1 ; Shift to get rid of
|
||
Shl BL, 1 ; unused bits
|
||
Mov CX, 6 ; Number of bits left
|
||
Mov DX, 5+Offset AllFlagList; Storage of abbreviations
|
||
|
||
AttrListLoop: Push DX ; Save abbreviation pointer
|
||
Shl BL, 1 ; Shift bit into carry
|
||
Jc FlagIsOn ; See if it's on
|
||
Mov DX, Offset AllFlagList ; If not, print blanks
|
||
|
||
FlagIsOn: Mov AH, 9 ; Print string
|
||
Int 21h ; by calling DOS
|
||
Pop DX ; Get back abbreviation ptr
|
||
Add DX, 5 ; Kick up for next bit
|
||
Loop AttrListLoop ; And loop around
|
||
Mov AL, 13 ; Print carriage return
|
||
Call DisplayChar
|
||
Mov AL, 10 ; Print line feed
|
||
Call DisplayChar
|
||
|
||
FindNextFile: Mov AH, 4Fh ; Find next file
|
||
Jmp FindFile ; By looping around
|
||
|
||
NoMoreFiles: Int 20h ; Terminate
|
||
|
||
; SUBROUTINE: Display Character in AL
|
||
; -----------------------------------
|
||
|
||
DisplayChar: Push AX
|
||
Push DX
|
||
Mov DL, AL ; Move character to DL
|
||
Mov AH, 2 ; Display it
|
||
Int 21h ; by calling DOS
|
||
Pop DX
|
||
Pop AX
|
||
Ret
|
||
|
||
; Some data stored at end to cut down COM size
|
||
; --------------------------------------------
|
||
|
||
DTABuffer Label Byte ; For file find calls
|
||
PathAndFile equ DTABuffer + 43 ; For file path and name
|
||
CSEG EndS ; End of the segment
|
||
End Entry ; Denotes entry point
|
||
|