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Assembly Source File | 1990-01-05 | 58.3 KB | 980 lines

PAGE 60,132 TITLE CHKFILEC - High performance file checker - compressed. ; SUBTTL General program description and use of common storage ; ----------------------------------------------------------------------------; ; CHKFILEC - characterize files by check values, time, date and size. ; ; ----------------------------------------------------------------------------; ; CHKFILE 1.0 ■ PCDATA TOOLKIT Copyright (c) 1990 Ziff Communications Co. ; ; PC Magazine ■ Wolfgang Stiller ; ; ; ; Purpose: ; ; CHKFILEC will read files and then characterize them with unique ; ; check values, update date, update time and file size. This data ; ; will be written in compressed form to the report file. This ; ; data can be used to validate file integrity by using program ; ; CFcompC to compare the report files and report any changes. ; ; ----------------------------------------------------------------------------; ;Format: ; ; ; ;CHKFILEC filespec1 filespec2 [/D] [/I:aa] [/T] [/1] [/2] ; ; ; ; filespec1 is the file specification for the file(s) to read. Wild cards ; ; such as * or ? can be used as well as a drive or directory. ; ; filespec2 will contain compressed report of file check data for CFcompC. ; ; "/D" Display directory entries as well as regular files ; ; "/I:aa" Ignore files beginning with characters aa (must be 2 chars). ; ; "/T" Ignored if coded. Totals are always generated. ; ; "/1" Utilizes an alternate algorithm for check value 1. ; ; "/2" Utilizes an alternate algorithm for check value 2. ; ; ; ; ----------------------------------------------------------------------------; ;Remarks: ; ; CHKFILEC has been specifically designed for high speed operation using ; ; a minimal of resources. It will run on any DOS PC with at least 64K ; ; free memory. CHKFILEC will read all files independent of whether they ; ; have the hidden or the system attribute set. CHKFILEC produces a ; ; report line for each file (and optionally directory) matching the ; ; primary file specification. CHKFILEC will report for each file in the ; ; current or specified directory the following information: File status ; ; byte, file or directory name, check value 1, check value 2, file size, ; ; and the DOS date and time of last update. This information is written ; ; to the report file specified in filespec2. All values are written in ; ; compressed (binary) form to this file. The file status byte identifies ; ; the file type and whether a read or open error occurred while ; ; processing the file. The filename is encrypted to make it more ; ; difficult to locate and modify this file. The report file in addition ; ; to always containing totals of the check values, contains 32 bits of ; ; internal check information which makes makes the file self-checking. ; ; CFcompC verifies this check data and will refuse to process any report ; ; file which has been damaged. ; ; ; ; If CHKFILEC encounters an error related to misuse of its parameters, it ; ; will produce an error message followed by a beep and a request for a ; ; key press. After a key press, it will display a description of the ; ; correct syntax. ; ; ; ; Both check values utilize a very high speed algorithm for computation. ; ; Check value 1 is an arithmetic sum (or difference for /1) of all bytes ; ; in each file being checked. Check value 2 utilizes a high speed hash ; ; type algorithm which utilizes circular shifts and the exclusive or ; ; function to generate a unique 16 value which is dependent not only on ; ; the value of each byte in the file, but the order of those values. If ; ; /1 or /2 are specified, either or both of these algorithms can be ; ; changed. This change is done at initialization time, so that the speed ; ; of the check value computation is not affected by these options. The ; ; /1, /2 and /T options are provided mainly to make CHKFILEC compatible ; ; with CHKfile. ; ; ; ; ----------------------------------------------------------------------------; ; CHKFILEC will report for each file in the current or specified directory ; ; the following information: ; ; Name of file, check values, (two 16 bit values ), the DOS time ; ; and date stamps of the file, and file size in hex bytes ; ; ; ; Format for report (filespec2) lines: Field size in bytes: ; ;File File Name + Chk Chk File Update Update 1 ; ;Type Extension: Val1 Val2 Size: Date: Time: 1 ; ;---- ------------ ---- ---- -------- -------- -------- 1__________ ; ; T filename.ext xxxx yyyy FileSize mm/dd/yy hh:mm:ss 1 ; ; 1 1 1 1 1 1 1 1 ; ; 1 1 1 1 1 1 1__Time of last update 2 ; ; 1 1 1 1 1 1__________ Date of last update 2 ; ; 1 1 1 1 1____________________ Size of file in bytes 4 ; ; 1 1 1 1___________________________ Check value2 for file 2 ; ; 1 1 1________________________________ Check value1 for file 2 ; ; 1 1_________________________________________ File name(encrypted) 12 ; ; 1___________________________________________________1=file 2=directory 1 ; ; Total record length for report file (REP_REC) is 25 bytes. ; ; ; ; ** See REP_REC definition for detail on field sizes ** ; ; ; ; Check value 1 - Is a modified check sum or difference - 16 bits. ; ; Check value 2 - Is a modified cumulative XOR of each character in ; ; file - 16 bits. ; ; ; ; The entire report file once written is self-checking because of the ; ; Totals record which is written out after all file check records. ; ; The totals record contains a final 32 bits of check data which is ; ; calculated by a different algorithm than that used by the files. This ; ; Check data will be validated each time the report file is read. ; ; ; ; ----------------------------------------------------------------------------; ; CHKFILEC will return the following DOS ERRORLEVELs: ; ; ; ; 00 - Normal completion - at least one file was reported. ; ; 04 - No files were checked. Either none match the filespec or all ; ; matched files were ignored by the /I parameter. ; ; 08 - Normal processing except open or I/O error detected on a file being ; ; checked. ; ; 32 - Open or write failed to the report output file ; ; 64 - (40h) Program failure due to invalid path or drive specified. ; ; 128 - (80h) Syntax error or missing parameters on program initiation. ; ; ; ; ----------------------------------------------------------------------------; ;---------------------------------------------------------------; ; Constants: ; ;---------------------------------------------------------------; BOX EQU 254 ;Small box character code CR EQU 0Dh LF EQU 0Ah CRLF EQU 0A0Dh ;Carriage return line feed. CSEG SEGMENT ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG ;---------------------------------------------------------------; ; D T A description (data transfer area): ; ;---------------------------------------------------------------; ORG 80h ;DTA and parameter line in PSP DTA_start DB 21 DUP (?) ; Reserved part of DTA + parm start DTA_F_attr DB ? ; File attribtute DTA_F_time DW ? ; File time DTA_F_date DW ? ;File date DTA_FS_lowr DW ? ;File size lower part DTA_FS_HIr DW ? ;File size upper part DTA_F_name DB 13 DUP(?) ;File name and extension SUBTTL Main program ;******************************************************************************; ;** Main program begins here -CHKFILEC- **; ;******************************************************************************; ORG 100h ; THIS IS A COM TYPE PROGRAM CHKFILEC: CALL Parse_parms_Print_Header ;Parse cmdline paramters + prnt header ; + find first match on file name ; ----------------------------------------------------------------------------; ; F O R M A T F I L E I N F O ; ; Process information extracted from the directory entries (the DTA) ; ; ----------------------------------------------------------------------------; ; GENERAL ALGORITHM: ; ; 1) Check if this is a .. or . directory or a file to ignore (/I:xx) ; ; If its to be ignored, go try to do another FIND NEXT generic match. ; ; 2) Extract file name, size, date and time from the DTA. ; ; 3) IF its a directory, indicate by placing DIR. in the checksum field, ; ; otherwise the file will be opened and processed. ; ; ----------------------------------------------------------------------------; Format_File_Info: ;----------------------------------------------------------------------------; ; Check if this is a file name to ignore (the .. and . directories or a file ; ; begining with xx from the "/I:xx" command line parameter). ; ;----------------------------------------------------------------------------; MOV SI, offset DTA_F_Name ;Move FROM DTA file name field MOV AX,WORD PTR [SI] ;load 1st 2 chars of this file name CMP AL,'.' ;Is it a "." or ".." directory? JNE Check_For_Ignore_files ; No, so check for ignore files JMP Find_Next_File ; Yes, it is so skip this file Check_For_Ignore_Files: CMP AX,Ignore_F_Name ;Is this the file name to ignore? JNE Xtract_DTA_Info ; No, so go ahead + process this file JMP Find_Next_File ; Yes, so skip this file... ;----------------------------------------------------------------------------; ; Extract info from the DTA (data transfr area) ; ; Extract file name, size and update date and time. ; ;----------------------------------------------------------------------------; Xtract_DTA_Info: MOV Files_Found,'Y' ;Indicate at least 1 file was matched! MOV CX,12 ;Scan 12 characters of filename (max) ; SI= offset DTA_F_Name ;SI already contains loc of DTA_F_NAME MOV DI, offset Rep_F_Name ;Move to output record file name Xfer_file_name: ;transfer filename from DTA to Rep_rec LODSB ;Load one byte from DTA for transfer OR AL,AL ;See if this=0 (end of file name) JZ Zero_fill ;If end, then zero fill rest of name ROL AL,1 ;Do quick and dirty encryption STOSB ;Else store char in REP_Rec file name LOOP Xfer_file_name ;continue until done JMP Short Extract_F_Size ;Go and format file size for output Zero_fill: ;zero fill remainder of file name MOV AL,0 REP STOSB ;Store remaining characters ; --------------------------------------------------; ; Extract file size from DTA for display ; ; --------------------------------------------------; Extract_F_size: ;Format DTA's file size for output MOV AX,DTA_FS_HIr ;High portion of file size MOV Rep_FS_Hir,AX ; transfer it onto report file MOV AX,DTA_FS_Lowr ;lower portion of file size MOV Rep_FS_Lowr,AX ; transfer it onto report file ; --------------------------------------------------; ; Extract file date from DTA for display ; ; --------------------------------------------------; MOV AX,DTA_F_date ;Date of last file update MOV Rep_F_Date,AX ; Transfer file date to report file ; date is in yyyyyyym mmmddddd format (year is offset from 1980) ; --------------------------------------------------; ; Extract file time from DTA for display ; ; --------------------------------------------------; MOV AX,DTA_F_time ;time of last file update ; time is in hhhhhmmm mmmsssss format (seconds are 0-29 in 2 sec intervl) MOV Rep_F_Time,AX ; transfer to the report file ; Check if this file is a directory entry rather than a file TEST DTA_F_attr,00010000B ;Check directory bit of file attribute JZ Open_the_File ;If not continue with normal process ; Do special handling for directory entries (rather than file entries): MOV Rep_F_Type,2 ;2 means this is a directory Finish_with_Zero_Check_Vals: ;Termnate with zeros in chk val fields MOV Rep_CHK_Sum,0 ;Zero the check value 1 on report file MOV Rep_XOR_Sum,0 ;Zero the check value 2 (XOR sum) JMP Write_Rep_Rec ;Skip rest of processing and go write ; this dir entry + find next file ; --------------; ; Open the file ; ; --------------; Open_the_File: MOV Rep_F_Type,1 ;1 means this is a file not a dirctry MOV DX,offset DTA_F_name ;point to file name in DTA MOV AX,3D00h ;DOS open file (handle) for read cmnd INT 21h ;invoke DOS JNC Continue_Open ;If no errors continue processing ; a report that open failed ; This open should never fail...(OS2 can have files open which will cause fail) MOV File_Error_Flag,'Y' ;Indicate that file had serious error MOV Rep_F_Type,3 ;3 means open fail on THIS file JMP SHORT Finish_with_Zero_Check_Vals ;No valid CHK vals avail Continue_Open: MOV BX,AX ;Save file handle XOR BP,BP ;zero out (clear) EOF indicator ; -------------------------------------------; ; Initialize check values for each file. ; ; -------------------------------------------; MOV DI,BP ;Zero check sum (check val 1) MOV DX,BP ;Zero XOR sum (check value 2) ; ----------------------------------------------------------------; ; START OF LOOP TO READ AND SCAN RECORDS ; ; ----------------------------------------------------------------; ; REGISTER USAGE CONVENTIONS IN READ_FILE LOOP: ; ; ; ; AL - Each new character read into this register ; ; BP - EOF (End Of File) indicator (flag) ; ; BX - Contains current file handle ; ; CX - number of chars read in -decreasing counter ; ; DI - Contains check value 1 for this file (CHKSUM) ; ; DX - Check value 2 for file and periodically start of buffer ; ; SI - index pointing into file BUFFER ; ; ----------------------------------------------------------------; Read_File: PUSH DX ;Save the XOR sum (check value 2) MOV DX,OFFSET Buffer ;INPUT BUFFER MOV SI,DX ;SI is for BUFFER reads later MOV CX,0FC00h ;MAX # of bytes to read MOV AH,3Fh ;Setup to read from file INT 21h ;Call DOS POP DX ;Resume using DX for check val 2 JNC Read_was_OK ;IF neither error nor EOF occurred. MOV File_Error_Flag,'Y' ; No, we've got a read error MOV Rep_F_Type,4 ; 4 means read error JMP SHORT Done_reading ; Write out this REP_REC Read_was_OK: OR AX,AX ;Check if ax=0 no records read JZ Done_reading ;If no records, close this file.. CMP AX,CX ;See of max number or records read JE Skip_EOF_ind ;If we have compltly filled buffer MOV BP,SP ; Else put EOF indicator in BP Skip_EOF_ind: ;Jump here to skip setting EOF MOV CX,AX ;SAVE # of BYTES read in CX JCXZ Done_reading ;Quit if nothing read XOR AH,AH ;Zero upper part of AX for addition ; Innermost read char loop - keep this fast! NEXT_CHAR: LODSB ;Get char into AL XOR DL,AL ;cumulative XOR into DX - Chck val 2 ;following instr modified by /2 parm ROL_op: ROL DX,1 ;Keep shifting to XOR sum to right ;following instr modified by /1 parm ADD_op: ADD DI,AX ;cumulative check sum - Chck val 1 LOOP NEXT_CHAR ;CONTINUE SCANNING CHARS UNTIL EOB OR BP,BP ;Check EOF indicator (=77h if EOF) JNZ Done_reading ;IF EOF, quit this file... JMP SHORT Read_File ;TRY TO READ SOME MORE Done_reading: ;Come here on EOF or error reading MOV AH,3Eh ;Prepare to close the file INT 21h ;Let DOS close file MOV Rep_CHK_Sum,DI ;Put check sum (chk val 1) in rep rec MOV Rep_XOR_Sum,DX ;Do same with XOR sum (check val 2) ADD Tot_CHK_Sum,DI ;Total check value 1 for all files ADD Tot_XOR_Sum,DX ;Total check value 2 for all files ;---------------; ; Write Rep_REC ; ;---------------; Write_Rep_Rec: MOV DX, offset Rep_rec ;prepare to write output record MOV CX,25 ;25 chars in Rep_rec MOV BX,Filespec2_Handle ;Handle for std output device MOV AH,40h ;DOS Write function INT 21h JNC Calc_Global_CHK_data ;If write was OK, then continue JMP Report_Write_Error ;Else notify user of fatal error ;-----------------------------------------------------------------------; ; CALC GLOBAL CHECK DATA - Calculate global checksum and XOR values for ; ; the report file. This information allows the report file to be ; ; self checking. Any change to it can then be detected. ; ;**Note, this algorithm is different than that used for file checking** ; ;-----------------------------------------------------------------------; Calc_Global_CHK_Data: MOV SI,DX ;Get start of buffer to calc chk data ;CX should still contain 25 (rec len) MOV DX,Rep_Rec_XORval ;Pick up cumulative XOR from before MOV BX,Rep_Rec_CHKsum ;Get last CHKsum(for entire rep file) CALL Calc_Sums ;Accumulate check values for this rec MOV Rep_Rec_XORval,DX ;Save cumulative XOR value MOV Rep_Rec_CHKsum,BX ;Save cumulative CHKsum ;-------------------------------; ; Search for next matching file ; ;-------------------------------; Find_Next_File: MOV AH,4Fh ;Search for next matching file INT 21h ;Do search JC Finish_Processing ;If no more matches, terminate. JMP Format_File_Info ;If no errors, process this file Finish_Processing: ;Else, Prepare to terminate ;If no files matched the filespec1 and were not ignored (/I:__) then just ;write a one byte zero record to indicate no matches. CMP Files_Found,'Y' ;Were any files at all checked? JE Write_Totals_record ; If so, write out totals record JMP No_Files_Matched ; Else just write zero record Write_Totals_Record: ; Move cumulative file totals into Rep_REC for display MOV DI,Tot_CHK_Sum ;Prepare cumulative totals for dsply MOV DX,Tot_XOR_Sum MOV Rep_CHK_Sum,DI ;Xfer to coorespnding report fields MOV Rep_XOR_Sum,DX ; Now save check data for this entire report file as the last 4 bytes: MOV DX,Rep_Rec_XORval ;Pick up cumulative XOR val MOV BX,Rep_Rec_CHKsum ;Get cumulative CHKsum value MOV Rep_FS_Lowr,DX ;Save XOR on file MOV Rep_FS_HIr,BX ;Save CHKsum ; Write the cumulative file totals and check data line MOV DX, offset Rep_CHK_SUM ;Write totals rec (only chk+Xor sums) MOV AH,40h ;Write function MOV BX,Filespec2_Handle ;Report file handle MOV CX,8 ;Write only first 8 chars INT 21h ;Actually write out the totals line JNC Check_drive_path_changes ;If write, was OK Report_Write_Error: MOV DX, OFFSET Write_fail_Msg ;tell user of I/O error MOV AH,09h ;DOS display string function INT 21h ;-----------------------------------------------------------------------; ; NORMAL TERMINATION starts here. All termination conditions where at ; ; least some records were matched begin here. ; ;-----------------------------------------------------------------------; ; 1) Restore user back to his original drive and path (if changed) ; ; 2) Close the report file ; ; 3) Set error level of 8 if we had file IO or open problems ; ; 4) Terminate with errorlevel of 0 (all is OK) or 8 ; ;-----------------------------------------------------------------------; Check_drive_path_changes: Call Restore_Original_Path ;Set back to original path if changd Call Restore_Original_Drive ;Set back to original drive if changd MOV BX,Filespec2_handle ;Prepare to close the report file MOV AH,3Eh ;DOS Close function INT 21h MOV AL,00h ;Plan on termination with 0 errlvl CMP File_Error_Flag,'Y' ;Did we get a file I/O error ? JNE End_Execution ; If not, term with 0 error level MOV AL,08h ; Else, terminate with 8 error level End_Execution: ;Successful termination of program MOV AH,4Ch ;terminate with error level in AL INT 21h SUBTTL General Purpose subroutines PAGE ;******************************************************************************; ;** General purpose subroutines follow **; ;******************************************************************************; ;------------------------------------------------------------------------------; ; Restore orginal drive - if disk changed, set back to original disk. ; ;------------------------------------------------------------------------------; Restore_Original_Drive: ;Set back to original drive if changd CMP Drive_Spec_Present,'Y' ;Did user overide drive? JNE Restore_Drive_RET ;If not then return to caller MOV DL,Old_disk ;get original drive MOV AH,0Eh ;Set current drive function INT 21h Restore_Drive_RET: RET ;------------------------------------------------------------------------------; ; Restore orginal path - if path changed, set back to original disk. ; ;------------------------------------------------------------------------------; Restore_Original_Path: ;Set back to orignl path if changed CMP Path_Present,'Y' ;Did user overide path (Directory) JNE Restore_Path_RET ;If not, return to caller MOV AH,3Bh ;Change current directory function MOV DX,offset Old_path ;Original path INT 21h ;Set path back to original Restore_Path_RET: RET ;---------------------------------------------------; ; C A L C _ S U M S - Calculate check values ; ;---------------------------------------------------; ; This is a special version for CFcompC + CHKFILEC. ; ;---------------------------------------------------; ; INPUT: SI = pointer to file BUFFER to scan ; ; CX = # of characters to read ; ; DX = cumulative XOR sum - check value 1 ; ; BX = cumulative CHK sum - check value 2 ; ; ; ;Register conventions: ; ; ; ; AL - Each new character read into this register ; ; CX - number of chars read in -decreasing counter ; ; BX - Contains checksum for this file ; ; DX - XOR check value ; ; SI - index pointing into file BUFFER ; ; ; ; None of above registers are saved and restored. ; ; --------------------------------------------------; Calc_Sums: XOR AH,AH ;Zero upper part of AX for addition Grab_next_char: LODSB ;Get char into AL ROR DX,1 ;Keep shifting to XOR sum to left XOR DL,AL ;cumulative XOR into DX SUB BX,AX ;cumulative check subtraction LOOP Grab_Next_Char ;CONTINUE SCANNING CHARS UNTIL EOB RET ;All done calculating sums! SUBTTL Definition of Data structures PAGE ;******************************************************************************; ;** Definition of Data areas follow **; ;******************************************************************************; File_Error_Flag DB 'N' ;='Y' indicates file IO or open error ;Report file record description: Rep_Rec EQU $ ;Name for the entire output record Rep_F_Type DB 0 ;Indicates if its a file (1) or dir(2) ;or file with open err(3) or IO err(4) Rep_F_Name DB 12 DUP (0) ;12 spaces reserved for filename Rep_CHK_Sum DW 0 ;Check sum: 16 bits Rep_XOR_Sum DW 0 ;Exclusive OR sum Rep_FS_Lowr DW 0 ;File size lower part of double word Rep_FS_HIr DW 0 ;File size: upper part of double word Rep_F_Date DW 0 ;Date of last file update: Rep_F_Time DW 0 ;Time of last file update Rep_Rec_XORval DW 0 ;Global cumulative XOR value(rep rec) Rep_Rec_CHKsum DW 0 ;Global cumulative CHK value(rep rec) Old_Path DB '\' ;Force 1st char of save area to = '\' DB 64 DUP (0) ;Save area to restore original path Old_Disk DB 0 ;Save area for original drive spec Drive_Spec_Present DB 0 ;Set = to "Y" if drive spec present Path_Present DB 0 ;Set = to "Y" if path specified Tot_CHK_Sum DW 0 ;total of all check sums (all files) Tot_XOR_Sum DW 0 ;total of exclusive or sums Ignore_F_Name DW ' ' ;ignore file names starting with this Filespec2_handle DW 0 ;Handle for the report file Files_Found DB 'N' ;Indicates in any files matched:Y or N Write_fail_Msg DB 'File2 write failed',CR,LF,'$' SUBTTL INIT data and code which is also input BUFFER PAGE ;******************************************************************************; ;** Definition of file buffer Data areas and code follow: **; ;** All the following storage will be overlaid when records are read in **; ;******************************************************************************; Buffer label byte ;All storage + code following is in ; the input file buffer. ; address must be less than 3F0 hex. ; ----------------------------------------------------------------------------; ; Initialization code - parse parms + put out msgs and find intial file match ; ; ----------------------------------------------------------------------------; Parse_parms_Print_Header: ;Parse input parameters + print header MOV SI,80h ;Parameter area in PSP MOV CL,[SI] ;Get # of chars in input parm XOR CH,CH ;Clear upper byte of char count OR CL,CL ;Check for 0 chars (NO INPUT) MOV BP,128 ;Error level code for syntax error JZ Display_Syntax_Msg ;IF no parms, put out help information INC SI ;Point to 1st character CLD ;FORWARD DIRECTION Del_Spaces: LODSB ;Get byte at DS:SI and inc SI CMP AL,' ' ;Is it a space? JNE Set_File_names ;If not we have a file name.. LOOP Del_Spaces ;continue checking until last char MOV BP,128 ;Error level code for syntax error JMP SHORT Display_Syntax_Msg ;Explain syntax to user Syntax_Err_Exit: ;Come here on syntax error MOV AH,09h ;DOS display string function INT 21h CALL Wait_For_Key ;Beep + force user to hit a key{ Display_Syntax_Msg: MOV DX, OFFSET Syntax_Msg ;Prepare ERROR Message MOV AH,09h ;DOS display string function INT 21h Call Restore_Original_Drive ;Set back to original drive if changd MOV AX,BP ;Get error level in AL from lower BP MOV AH,4Ch ; terminate with errorlevel in AL INT 21h ;---------------------------------------------------------------------------; ; Conventions for command line parsing: ; ; SI points to next char to be checked in the parm field at DS:80 ; ; CX is count of characters left to be scanned ; ; BP points to start of filespec1 for find next processing ; ;---------------------------------------------------------------------------; ;----------------------------------------; ; Parse filespec1 and xfer in msg field ; ;----------------------------------------; Set_File_Names: CMP BYTE PTR [SI],':' ;Check for presence of drive spec JNZ Read_file_spec AND AL,5Fh ;Capitalize drive letter SUB AL,'A' ;Convert to numeric form MOV New_Drive,AL ;Save num drive - change to it later MOV Drive_spec_present,'Y' ;Indicate user is overriding drive MOV AH,19h ;DOS get current drive function INT 21h MOV Old_disk,AL ;Save current disk ADD SI,2 ;adjust pointers and SUB CX,2 ; counters to skip drive spec Read_file_spec: DEC SI ;point back to 1ST letter of filespec MOV BP,SI ;Save a copy of filespec start MOV DI, offset User_File_Spec ;prep to transfer file name to msg Scan_To_File_Spec_End: ; start scanning the file specification and transfer into output field LODSB ;Get next char of file spec CMP AL,' ' ;check valid separator character JBE File_Spec_End_Found CMP AL,' ' ;check valid separator character JE File_Spec_End_Found STOSB ;Store char as part of User_file_spec LOOP Scan_To_File_Spec_End INC SI ;Adjust BX if no separator char found File_Spec_End_Found: MOV BX,SI DEC BX ;= next char loc after filespec MOV BYTE PTR [BX],00 ;zero terminate the filespec: ASCIIZ PUSH AX ;Save last char examined MOV AX,CRLF ;Put out carriage return line feed STOSW ; combination as a single word MOV AL,LF ;Include extra line feed STOSB POP AX ;Restore last character examined ;---------------------------------------------------------------------------; ; Parse filespec2: (Not a called subroutine - just a code module) ; ; Input: ; ; SI points to next char to be checked in the parm field at DS:80 ; ; CX is count of characters left to be scanned ; ; ; ; Returns: ; ; DI points to byte after last char in filespec ; ; Filespec is zero terminated in the parameter area ; ;---------------------------------------------------------------------------; Parse_Filespec2: ;Extract and zero terminate filename OR CL,CL ;Check for 0 chars (NO INPUT) JZ Bad_filespec2 ;If no parms, display error message Del_Spaces2: LODSB ;Get byte at DS:SI and inc SI CMP AL,' ' ;Is it a space? JNE Get_Filespec2 ;If not, we should have a file name.. LOOP Del_Spaces2 ;Continue checking until last char Bad_Filespec2: MOV DX, OFFSET Bad_file2_Msg ;tell user filespec2 is needed MOV BP,32 ;Terminate with 32 (20h) err lvl JMP Syntax_Err_Exit ;Display error msg + correct syntax ;--------------------------------------------; ; Parse file spec and zero byte terminate it ; ;--------------------------------------------; Get_Filespec2: DEC SI ;point back to 1ST letter of filespec MOV File2_Start,SI ;Save a copy of filespec2 start Scan_to_filespec2_end: ; start scanning the file specification and transfer into output field LODSB ;Get next char of file spec CMP AL,' ' ;Check valid separator character JBE Filespec2_End_Found CMP AL,'/' ;Check for valid separator JE Filespec2_End_Found CMP AL,',' ;Check for valid separator JE Filespec2_End_Found LOOP Scan_to_filespec2_end INC SI ;Adjust SI if no separator char found Filespec2_end_found: DEC CX ;Correct the char remaining count ; SI is pointing 2 characters past end of filespec at this time MOV DI,SI DEC DI ;DI points to 1st char after filespec2 MOV BYTE PTR [DI],00 ;zero terminate filespec2: ASCIIZ ;---------------------------------------------------; ;Check parameter characters left. ; ;At this point we begin the scan for the /x type ; ;Parameters. (if any). ; ;---------------------------------------------------; Check_parm_chars_left: ;Check if enough chars left for a parm CMP CX,01 ;Check if we out of chars to scan JA Parm_Scan ; if not continue chcking for /parms JMP Open_Filespec2 ; If so, cont with next step of init Parm_Scan: ;Check for presence of a /_ parm CMP AL,'/' ;check for "/" parm character JE Parm_found CMP AL,' ' ;check for blanks JNE Unrecog_parm ;If other than blank its illegal... LODSB ;Keep checking next character LOOP Parm_Scan JMP short Open_Filespec2 ;Continue with initialization... Parm_Found: ;Check if parm is valid DEC CX ;Adjust chars remaining counter JCXZ Unrecog_parm ;IF no chars left then parm is invalid LODSB ;Get next char DEC CX ;Adjust chars remaining counter CMP AL,'2' ;Is it alternate chk val 2 (XOR) parm? JE X2_parm ;exclusive or parm detected (/2) CMP AL,'1' ;Is it alternate Chk val 1 (Sum) parm? JE C1_parm ;/1 parameter detected.. AND AL,5Fh ;Capitalize char CMP AL,'T' ;Is it the "Totals wanted" parm? JE T_parm ;T parameter detected CMP AL,'D' ;Is it Directory display parm? JE D_parm ;D parameter detected.. CMP AL,'I' ;Is it Ignore file parm? JE I_parm ;I parameter detected.. else its... Unrecog_parm: ; an illegal paramter: MOV DX, offset Bad_Parm_MSG ;indicate illegal parm was found MOV BP,128 ;Error level code for syntax error JMP Syntax_ERR_Exit ;terminate with error level set ;T parm is maintained for compatibility with CHKFILE only...it is ignored T_parm: ;This parameter has no effect LODSB ;Keep checking next character JMP SHORT Check_Parm_chars_left ;Check for additional parms X2_parm: MOV WORD PTR [ROL_op],0CAD1h ;patch ROL op code into ROR DX,1 op LODSB ;Keep checking next character JMP SHORT Check_Parm_chars_left ;Check for additional parms C1_parm: ;Use of alt CHK sum algor(/1 parm) MOV WORD PTR [ADD_op],0C729h ;patch ADD op code into SUB DI,AX op LODSB ;Keep checking next character JMP SHORT Check_Parm_chars_left ;Check for additional parms D_parm: MOV WORD PTR [File_Attrib],0017h ;Change file attrib to incl DIRs LODSB ;Keep checking next character JMP SHORT Check_Parm_chars_left ;Check for additional parms I_parm: CMP CX,03 ;We must have at least 3 chars left JB Unrecog_parm ;If not, this is a bad parameter LODSB ;Check next character CMP AL,':' ; it should be ':' JNE Unrecog_parm ;If not, its bad parm time again.. SUB CX,03 ;Adjust chrs remaining counter LODSW ;Get file prefix to ignore ; Now capitalize the file name prefix, only if lower case alphabetic CMP AL,'a' ;could this be a lower case alpha? JB Check_2nd_char ;If not go ahead and check other char CMP AL,'z' ;could this be a lower case alpha? JA Check_2nd_char ;If not go ahead and check 2nd char AND AL,5Fh ;Bump character into uppercase Check_2nd_char: ;Now check the 2nd file ignore char CMP AH,'a' ;could this be a lower case alpha? JB I_store ;If not go ahead and store the char CMP AH,'z' ;could this be a lower case alpha? JA I_store ;If not go ahead and store the char AND AH,5Fh ;Bump character into uppercase I_store: MOV Ignore_F_Name,AX ;Store file prefix (for ignore) LODSB ;Keep checking next character JMP Check_Parm_chars_left ;Check for additional parms Invalid_path: MOV DX,offset Bad_path_MSG ;Indicate problem with path MOV BP,64 ;Errorlevel for bad drive or path JMP Syntax_Err_Exit ;Report error+displ correct syntax ;--------------------------------------; ; Open the report file (filespec2): ; ;--------------------------------------; Open_Filespec2: MOV DX,File2_Start ;DX contains filespec2 start MOV AH,3Ch ;DOS create and truncate file func XOR CX,CX ;Set CX=0, means normal file attrib INT 21h ;invoke DOS JNC Filespec2_Open_OK ;If no errors continue processing MOV DX, OFFSET F2_open_fail ;tell user filespec2 open failed MOV BP,32 ; terminate with 32 error level JMP Syntax_Err_Exit ;Display error followed by syntax Filespec2_Open_Ok: MOV Filespec2_handle,AX ;Save the file handle ;--------------------------------------------------------------; ; Set system default disk drive to that specified in filespec1 ; ;--------------------------------------------------------------; Set_Filespec1_New_Drive: CMP Drive_spec_present,'Y' ;Did user override drive spec? JNE Check_for_DIR ; No, then we don't need to change it MOV DL,New_Drive ; Else get numeric drive spec + chng MOV AH,0Eh ; DOS select disk function INT 21h ; Set to drive in filespec1 JNC Check_For_DIR ; Was the disk drive specified OK? JMP Invalid_Path ; If drive specified is invalid.. Check_for_DIR: ;See if PATH included in filespec1 MOV CX,BX ;End of filespec1 + 1 SUB CX,BP ;Calc length of filespec1 PUSH CX ;Save length for use later STD ;Prepare to scan filespec1 backwards MOV DI,BX ;Start from end DEC DI ; of filespec1 MOV AL,'\' ;Scan filespec1 for presence of "\" REPNE SCASB ;Scan to last \ from end of filespec1 CLD ;Reset direction flag to forward JNZ Display_Heading ;IF, no path found in filespec1 MOV Path_Present,'Y' ;Set flag to indicate path present INC DI ;Point to "\" character MOV BYTE PTR [DI],0 ;Zero terminate the PATH (clobber \) ;Determine current directory MOV SI,offset Old_path+1 ;Place to store original directory XOR DL,DL ;Zero DL in order to use default drive MOV AH,47h ;Get current directory (path) func INT 21h JC Invalid_path ;IF function failed(will never happen) ; prepare to set to user's specified file path (directory) MOV DX,BP ;Begining of dir in parm area CMP DI,BP ;Is \ 1st + only compnnt of dir stng? JNE Not_Root_Dir ;If \ is only char, this is root dir MOV DX, offset Root_Dir ; so set directory to root directory Not_Root_Dir: MOV AH,3Bh ;Set current directory function INT 21h JC Invalid_path ;IF function failed INC DI ;Point to start of filename1 (path+1) MOV BP,DI ;Set new filename start (skip path) ;----------------------------------------------------------------------------; ; Display the start message and the heading for the file list ; ;----------------------------------------------------------------------------; Display_Heading: MOV DX,OFFSET Start_MSG ;Put out main banner msg for output MOV AH,40h ;DOS DISPLAY STRING FUNCTION MOV CX,SM_End-Start_MSG ;# of chars in start msg MOV BX,1 ;Handle for std output device INT 21h MOV DX,OFFSET User_File_Spec ;Tell user what files we're checking MOV AH,40h ;DOS write file funct (std output) POP CX ;Get length of filespec1 ADD CX,3 ;add extra chars to length (CRLF LF) INT 21h ;----------------------------------------------------------------------------; ; Find first occurance of a file to match the possible wildcards in filespec1; ;----------------------------------------------------------------------------; Find_First_File: MOV DX,BP ;DX points to filename of filespec1 MOV AH,4Eh ;DOS find first command (use 80H DTA) MOV CX,File_attrib ;Set file attrib INT 21h ;Invoke DOS JNC Done_FFF ;If no carry, then all is OK.. No_Files_Matched: ;Come here when no files checked Call Restore_Original_Path ;Set back to original path if changd Call Restore_Original_Drive ;Set back to original drive if changd ; Report that no files were matched to the user MOV DX, OFFSET No_CHK_Msg ;Tell users no files matched MOV AH,09h ;DOS display string function INT 21h ; Write 1 byte record indicating no files matched MOV AH,40h ;DOS write file function MOV BX,Filespec2_handle ;Report file, file handle MOV CX,1 ;Write 1 byte zero record MOV DX,OFFSET Zero_Byte ;single hex zero to write INT 21h ;Write 1 byte of zero to report file JNC ClOSE_Report_File ;If write was OK, close file + finish JMP Report_Write_Error ;Notify user of fatal write error Close_Report_File: MOV AH,3Eh ;DOS Close function INT 21h ;Close the report file MOV AX,4C04h ; terminate with 04 error level INT 21h Done_FFF: RET ;---------------------------------------------------; ; W A I T F O R K E Y ; ;---------------------------------------------------; ; 1) Send out a BEEP ; ; 2) Determine screen attribute (screen colors) ; ; 3) Determine what line cursor is on ; ; 4) Put out message to hit any key on that line ; ; 5) Wait for any keypress ; ; 6) Erase message using current screen attribute ; ; 7) Position currsor back at start of current line.; ; --------------------------------------------------; ; *** ALL REGISTERS MAY BE CORRUPTED EXCEPT BP *** ; ; --------------------------------------------------; Wait_For_Key: ;Force user to notice error PUSH BP ;Save the only needed register ; Produce a beep to alert the user: (use BIOS TTY func to write an ASCII BELL) MOV AX,0E07h ;BIOS func (0Eh) to write (07H) beep XOR BH,BH ;Select page zero for output INT 10h ;BIOS video function (0Eh=write char) ;Find out what attribute is being used for display MOV AH,08h ;read attrib + char function INT 10h ;Call BIOS PUSH AX ;Save AH=attribute byte ;Find out what line the cursor is on MOV AH,03h ;Read cursor position function INT 10h ;BIOS video services PUSH DX ;DH contains row (line #) Save it! ; Position cursor to current line + column 28: (TO BIOS row 27) MOV AH,02 ;BIOS int 10h set cursor position func XOR BH,BH ;Set page to zero ;DH contains current row MOV DL,1Bh ;Set cusor current row and col 27 INT 10h ;BIOS video services ; Put -Hit any key- message out with inverse video attribute type on ; XOR BH,BH ;Set page to zero (BH is still 0) MOV BL,0F0h ;Inverse video attribute MOV CX,1 ;Character count MOV SI,offset Hit_Key_Msg ;The hit-any-key message Display_next_video_char: MOV AH,09h ;BIOS int 10h write attrib + char func LODSB ;Get next character for output PUSH SI ;Save SI (int 10h may corrupt it) INT 10h ;Put character and attribute out INC DX ;Advance cursor position MOV AH,02 ;Adv cursor function INT 10h ; advance the cursor (BIOS) POP SI ;Restore saved SI CMP SI,offset Hit_key_Msg_end ;are we at end of message? JB Display_next_video_char ; If not get next char for display ; Else, wait for key press by user ; Wait for user to hit any key XOR AX,AX INT 16h ;Wait for user to hit a key ; Erase HIT ANY KEY message POP DX ;DH=current line number POP BX ;BH=user's screen attribute MOV AH,06h ;INIT window function XOR AL,AL ;Zero AL to clear window MOV CH,DH ;Current row (y coor upr lft) MOV CL,00 ;Start in first char position MOV DL,79 ;Last char pos - blank entire line INT 10h ;Blank out line ; Position cursor to start of blanked line MOV AH,02 ;BIOS int 10h set cursor position func XOR DL,DL ;DH=cur line, DL=0: first char pos XOR BX,BX ;Use video page zero INT 10h ;BIOS video services POP BP RET ;Return to caller ; --------------------------------------------------; ; Initialization DATA STORAGE ; ; --------------------------------------------------; Root_dir DB '\' ;Zero terminated root dir string Zero_Byte DB 0 ;This must immed. follow Root_Dir File_Attrib DW 0007h ;File attribute (RO, hidden + sys) File2_start DW 0007h ;File attribute (RO, hidden + sys) New_Drive DB 0 ;Drive to change to in filespec1 Start_MSG DB CR,LF,"CHKFILEC 1.0 ",BOX," PCDATA TOOLKIT (c) 1990" DB " Ziff Communications Co.",CR,LF DB "PC Magazine ",BOX," Wolfgang Stiller - Checking: " SM_End LABEL BYTE ;End of the Start message Bad_Path_MSG DB 'Invalid path/drive on filespec1.',CR,LF,'$' Bad_Parm_MSG DB 'Unrecognized parameter detected.',cr,lf,lf,'$' Syntax_Msg DB "CHKFILEC 1.0 ",BOX," PCDATA TOOLKIT Copyright (c) 1990" DB " Ziff Communications Co.",CR,LF DB "PC Magazine ",BOX," Wolfgang Stiller",CR,LF,CR,LF DB 'CHKFILEC will read all files which match the specified file ' DB 'name, reporting',CR,LF DB 'two check values, plus DOS file size, date and time. This' DB ' information',CR,LF DB 'is written in compressed, self checking form to a separate' DB ' report file which',CR,LF DB 'can be used by CFcompC to validate file integrity.' DB CR,LF,LF DB 'Syntax is: CHKFILEC filespec1 filespec2 [/D] [/I:zz] ' DB '[/T] [/1] [/2]',CR,LF,LF DB ' filespec1 is the file specification for the file(s) to' DB ' check. Wild cards',CR,LF DB ' such as * or ? can be used as well as a drive' DB ' or directory.',CR,LF DB ' filespec2 is compressed report file of file check data.' DB CR,LF DB ' "/D" Display directory entries as well as files.' DB CR,LF DB ' "/I:aa" Ignore all files which begin with the 2 ' DB 'chars: aa.',CR,LF DB ' "/T" Ignored if coded. Totals are always generated.' DB CR,LF DB ' "/1" Utilize an alternate check value1 algorithm.' DB CR,LF DB ' "/2" Utilize an alternate check value2 algorithm.' DB CR,LF,'$' Bad_file2_msg DB '2nd file parameter (report file) is missing or bad.' DB CR,LF,'$' F2_Open_fail DB 'Open failed for filespec2 (report file)' DB CR,LF,'$' No_CHK_MSG DB 'No files were checked.' DB CR,LF,'$' Hit_Key_Msg DB '-Hit any key-' Hit_Key_MSG_end EQU $ User_file_spec EQU $ ;User specified file spec to check CSEG EndS END CHKFILEC