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/ Power-Programmierung / CD1.mdf / assemblr / mslang / dbhex / dbhex.asm next >

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Assembly Source File | 1993-04-03 | 21.4 KB | 933 lines

_MODEL equ <small> include MODEL.INC include CONSOLE.INC include FILEIO.INC include IMATH.INC .codeseg lib .extrn start:auto, exit_ok:auto .extrn console_init:auto, set_directvideo:auto .extrn open_h:auto,close_h:auto,read_h:auto .extrn str_len:auto,str_ncpy:auto,str_stri:auto,str_cat:auto .extrn put_str:auto,put_newline:auto,put_chr:auto .extrn byte_to_hex:auto,word_to_hex:auto,dword_to_asc:auto .extrn arg_next:auto .extrn getfsize_h:auto .ends .dataseg DBFNAME DB 128 DUP(0) DBEXT DB ".DBF",0 DBHANDLE DW 0 HEADERMSG DB '.DBF Header:',0 FLDDESCMSG DB 'Field Descriptor:',0 RECNOMSG DB 'Record Number ',0 FLDCOUNTER DB 0 BYTECOUNTER DD 0 BYTECNTRSTRING DB 5 DUP(0) FILESIZE DW 2 DUP(0) POS_COUNTER DB 0 ; Position counter, from 1 to 16 (0 to F) CURPOINTER DW 0 ; For saving SI or DI. BYTEHEXSTRING DB 3 DUP(0) VERSNO DB 0 LASTYEAR db 0 LASTMONTH DB 0 LASTDAY DB 0 RECCOUNT DD 0 HEADERLEN DW 0 RECLEN DW 0 DRESERVED1 DW 0 DRESERVED2 DB 0 DRESERVED3 DB 13 DUP(0) DRESERVED4 DB 0 DRESERVED5 DB 3 DUP(0) DESCLEN DW 0 NO_OF_FIELDS DB 0 FIELDNAME DB 11 DUP(0) FIELDTYPE DB 0 FIELDOFFSET DW 2 DUP(0) FIELDLENGTH DB 0 DECPLACE DB 0 FRESERVED DB 14 DUP(0) RECNO DD 0 ; Current Record Number RECNOSTRING DB 10 DUP(0) ; This will contain either the hex or ; decimal ascii string version of RECNO. LINES_PER_RECORD DW 0 ; Number of lines needed to display a record, ; not counting the bytes on the last line ; of each record block. REMAINING_BYTES DB 0 ; Number of bytes on last line of each record ; block; when all records are displayed, this ; becomes the number of bytes on the last line ; of the file. REMAINING_SPACES DB 0 ; Number of spaces to pad with on last line of ; block; when all records are displayed, this ; becomes the number of spaces to pad on the last ; line of the file. RECBLKCOUNTER DW 0 ; Counter to store which line of block is currently ; being read or displayed. RECORDDATA DB 16 DUP(0) ; This holds the actual data, which is then ; displayed in hex and ascii formats. TERMINATOR DB 0Dh ; This holds the terminator byte, which should ; always be 0D hex. NUM_BYTES_TO_READ DB 0 ; This is the number of bytes to be read. It is ; usually 16, unless the number of fields and/or ; the field widths in the database is small. It ; may become less than 16, though, e.g. for the ; last line of each record block. .ends .stackseg db 1024 dup(?) ;define a 1024 byte stack .ends .codeseg assume cs:@codeseg, ds:@dataseg, es:@dataseg, ss:@stackseg .public main .proc main auto MOV AX, @DATASEG MOV DS, AX BEGINNING: CALL CONSOLE_INIT CALL SET_DIRECTVIDEO MOV SI,OFFSET @DATASEG:DBFNAME CALL ARG_NEXT ; Get 1st argument - database name. CALL OPENDBF ; Try to open the file. CALL DISP_HDRSTRING ; Display '.DBF Header:' or similar heading. CALL GET_AND_DISP_HEADER ; Display hex and ascii forms of header. CALL CALCFROMHDR ; Calculate some relevant parameters from ; header. CALL DISP_DESCSTRING ; Display 'Field Descriptor:' or similar heading. CALL GET_AND_DISP_DESC ; Display hex and ascii forms of field descriptor ; array. CALL GET_AND_DISP_TERMINATOR ; Display terminator of field descriptor. CALL GET_AND_DISP_RECS ; Read records from disk and display. CALL LAST_BYTES ; Read and display the final byte(s). CALL CLOSE_AND_EXIT ; Close the database file and exit to DOS. ;============================================================================= ;Procedure: CLOSE_AND_EXIT ; ;DESC: Closes the .DBF file and exits. ; ;IN: DBHANDLE should contain the name of the open .DBF file. ; ;OUT: None ;============================================================================= .PROC CLOSE_AND_EXIT MOV BX,DBHANDLE ; Make sure the proper file handle is back in BX. CALL CLOSE_H CALL EXIT_OK .ENDP CLOSE_AND_EXIT ret ;exit to DOS with ERRORLEVEL=0 .endp main ;============================================================================= ;Procedure: DISP_HDRSTRING ; ;DESC: Displays a short description to appear above the .DBF header lines ; e.g., '.DBF Header:' ; ;IN: HEADERMSG should point to the desired description. ; ;OUT: None ;============================================================================= .PROC DISP_HDRSTRING PUSH SI MOV SI,OFFSET @DATASEG:HEADERMSG CALL PUT_STR CALL PUT_NEWLINE POP SI RET .ENDP DISP_HDRSTRING ;============================================================================= ;Procedure: DISP_DESCSTRING ; ;DESC: Displays a short description to appear above the .DBF descriptor ; lines. e.g., '.Field Descriptor:' ; ;IN: FLDDESCMSG should point to the desired description. ; ;OUT: None ;============================================================================= .PROC DISP_DESCSTRING PUSH SI MOV SI,OFFSET @DATASEG:FLDDESCMSG CALL PUT_STR CALL PUT_NEWLINE POP SI RET .ENDP DISP_DESCSTRING ;============================================================================= ;Procedure: DISP_HEXCHR ; ;DESC: Converts next number to ASCII hex, and displays. ; ;IN: AL contains byte to be displayed. ; ;OUT: BYTECOUNTER is incremented; POS_COUNTER is incremented; BYTEHEXSTRING ; contains ascii hex form of byte. ;============================================================================= .PROC DISP_HEXCHR .PUSH AX,DX,SI LODSB MOV SI,OFFSET @DATASEG:BYTEHEXSTRING CALL BYTE_TO_HEX CALL PUT_STR INC POS_COUNTER ; Keep track of where the cursor is in hex area. MOV DX,WORD PTR BYTECOUNTER[2] MOV AX,WORD PTR BYTECOUNTER[0] .INC_D DX,AX ; Increment doubleword at BYTECOUNTER MOV WORD PTR BYTECOUNTER[2],DX MOV WORD PTR BYTECOUNTER[0],AX .POP AX,DX,SI RET .ENDP DISP_HEXCHR ;============================================================================= ;Procedure: GET_AND_DISP_HEADER ; ;DESC: Reads header information, and displays offset, hex and ascii. ; ;IN: None ; ;OUT: BYTECOUNTER is incremented. ;============================================================================= .PROC GET_AND_DISP_HEADER .PUSH CX,SI MOV SI,OFFSET @DATASEG:VERSNO ; Read 32 bytes CALL GET_AND_DISP_16BYTES ; Read and display 16 bytes in hexadecimal ; format and ascii format. CALL GET_AND_DISP_16BYTES ; Same with the next 16 bytes. CALL PUT_NEWLINE .POP CX,SI RET .ENDP GET_AND_DISP_HEADER ;============================================================================= ;Procedure: GET_AND_DISP_DESC ; ;DESC: Reads and displays the field descriptor array. ; ;IN: None. ; ;OUT: BYTECOUNTER is incremented. ;============================================================================= .PROC GET_AND_DISP_DESC ; Get and Display field descriptor array .PUSH AX,CX,SI GET_AND_DISP_DESC1: MOV SI,OFFSET @DATASEG:FIELDNAME ; Each field descriptor is 32 bytes long. CALL GET_AND_DISP_16BYTES CALL GET_AND_DISP_16BYTES CALL PUT_NEWLINE INC FLDCOUNTER MOV AL,FLDCOUNTER ; Move the number of fields displayed so far ; into AL. CMP AL,NO_OF_FIELDS ; If the number of fields displayed is less ; the total number [ NO_OF_FIELDS ], then JB GET_AND_DISP_DESC1 ; display another field. .POP AX,CX,SI RET ; Return when all fields specs have been ; displayed. .ENDP GET_AND_DISP_DESC ;============================================================================= ;Procedure: GET_AND_DISP_TERMINATOR ; ;DESC: Reads and displays the terminator byte, which should be 0D, and ; which follows the field descriptor. ; ;IN: ; ;OUT: BYTECOUNTER is incremented. ;============================================================================= .PROC GET_AND_DISP_TERMINATOR .PUSH CX,SI MOV CL,1 MOV SI,OFFSET @DATASEG:TERMINATOR CALL GET_BYTES CALL DISP_OFFSET CALL DISP_BYTES MOV CL,45 ; There will always be 45 spaces to display on ; a terminator line, right after the terminator (0D) CALL PUT_SPACES ; so display them. MOV CL,1 CALL DISP_ASCII ; Now display the corresponding ascii form of ; TERMINATOR, which in our interpretation is a period. CALL PUT_NEWLINE CALL PUT_NEWLINE .POP CX,SI RET .ENDP GET_AND_DISP_TERMINATOR ;============================================================================= ;Procedure: CALCFROMHDR ; ;DESC: Using information from the header, calculates the length of the ; field descriptor array (DESCLEN), the number of fields (NO_OF_FIELDS), ; the number of hex/ascii lines to be displayed for each record ; (LINES_PER_RECORD), the number of bytes on the last line of each ; ; record block (REMAINING_BYTES) and the number of spaces to pad after ; the hex portion (REMAINING_SPACES). ; ;IN: None ; ;OUT: DESCLEN, NO_OF_FIELDS, LINES_PER_RECORD, REMAINING_BYTES, ; REMAINING_SPACES ;============================================================================= .PROC CALCFROMHDR .PUSH AX,BX,DX XOR DX,DX MOV AX,HEADERLEN SUB AX,33 MOV DESCLEN,AX ; Field descriptor length MOV BX,32 DIV BX MOV NO_OF_FIELDS,AL XOR DX,DX MOV AX,RECLEN MOV BX,16 DIV BX MOV LINES_PER_RECORD,AX MOV REMAINING_BYTES,DL MOV AL,DL CALL CALC_REM_SPACES .POP AX,BX,DX RET .ENDP CALCFROMHDR ;============================================================================= ;Procedure: CALC_REM_SPACES ; ;DESC: Calculates the necessary number of spaces to pad a line with, after ; the hex area and before the ascii area. ; ;IN: AL contains the number of hex bytes on the line. ; ;OUT: REMAINING_SPACES contains the number of spaces to pad with. ;============================================================================= .PROC CALC_REM_SPACES .PUSH AX,BX MOV BL,16 SUB BL,AL MOV AL,3 MUL BL MOV REMAINING_SPACES,AL .POP AX,BX RET .ENDP CALC_REM_SPACES ;============================================================================= ;Procedure: DISP_OFFSET ; ;DESC: Displays the offset from the current 64k block that is being processed, ; as well as a couple of spaces after the offset and before the rest of ; the hex/ascii output. ;IN: BYTECOUNTER contains the hex form of the offset ; ;OUT: BYTECNTRSTRING contains the string form of the offset ;============================================================================= .PROC DISP_OFFSET .PUSH AX,SI MOV SI,OFFSET @DATASEG:BYTECNTRSTRING MOV AX, WORD PTR BYTECOUNTER[0] CALL WORD_TO_HEX CALL PUT_STR CALL PUT_SPACE CALL PUT_SPACE .POP AX,SI RET .ENDP DISP_OFFSET ;============================================================================= ;Procedure: PUT_SPACES ; ;DESC: Displays cl number of spaces at the current cursor location. ; ;IN: CL contains number of spaces to display. ; ;OUT: None ;============================================================================= .PROC PUT_SPACES PUSH CX PUT_SPACES1: CALL PUT_SPACE LOOP PUT_SPACES1 POP CX RET .ENDP PUT_SPACES ;============================================================================= ;Procedure: PUT_SPACE ; ;DESC: Displays a space at the current cursor location. ; ;IN: None ; ;OUT: None ;============================================================================= .PROC PUT_SPACE PUSH AX MOV AL," " CALL PUT_CHR POP AX RET .ENDP PUT_SPACE ;============================================================================= ;Procedure: GET_AND_DISP_RECS ; ;DESC: Reads and displays all records from file. ; ;IN: None ; ;OUT: BYTECOUNTER is updated. ;============================================================================= .PROC GET_AND_DISP_RECS GET_AND_DISP_RECS1: .PUSH AX,BX,CX,DX MOV DX, WORD PTR RECNO[2] ; Bring high word of RECNO into DX MOV AX, WORD PTR RECNO[0] ; and low word into AX. MOV CX, WORD PTR RECCOUNT[2] ; High word of RECCOUNT into CX MOV BX, WORD PTR RECCOUNT[0] ; and low word into BX. .CMP_DD DX,AX,CX,BX ; Compare double words RECNO and RECCOUNT. .POP AX,BX,CX,DX JE GET_AND_DISP_RECSEND ; If RECNO is now the same as RECCOUNT, ; stop displaying records. CALL DISP_RECNO ; Display hex/decimal string form of record number. CALL GET_AND_DISP_REC ; Read record from file, and display it in ; hex and ascii formats. CALL PUT_NEWLINE JMP GET_AND_DISP_RECS1 ; Loop back to get and display another record. GET_AND_DISP_RECSEND: RET .ENDP GET_AND_DISP_RECS ;============================================================================= ;Procedure: DISP_RECNO ; ;DESC: Displays the current record number, in hex and decimal ascii formats. ; ;IN: None ; ;OUT: Increments RECNO. ;============================================================================= .PROC DISP_RECNO .PUSH AX,BX,CX,DX,SI XOR CH,CH MOV CL,11 CALL PUT_SPACES MOV SI,OFFSET @DATASEG:RECNOMSG CALL PUT_STR MOV DX,WORD PTR RECNO[2] MOV AX,WORD PTR RECNO[0] .INC_D DX,AX ; Increment double word at RECNO. MOV WORD PTR RECNO[2],DX MOV WORD PTR RECNO[0],AX MOV BL,16 MOV SI,OFFSET @DATASEG:RECNOSTRING CALL DWORD_TO_ASC CALL PUT_STR MOV AL,'h' CALL PUT_CHR MOV AL,'/' CALL PUT_CHR MOV DX,WORD PTR RECNO[2] MOV AX,WORD PTR RECNO[0] MOV BL,10 MOV SI,OFFSET @DATASEG:RECNOSTRING CALL DWORD_TO_ASC CALL PUT_STR MOV AL,'d' CALL PUT_CHR MOV AL,':' CALL PUT_CHR CALL PUT_NEWLINE .POP AX,BX,CX,DX,SI RET .ENDP DISP_RECNO ;============================================================================= ;Procedure: GET_AND_DISP_REC ; ;DESC: Reads 16 bytes from file, and displays in hex and ascii format. ; ;IN: None ; ;OUT: BYTECOUNTER is updated. ;============================================================================= .PROC GET_AND_DISP_REC .PUSH AX,CX,SI GET_AND_DISP_REC1: MOV SI,OFFSET @DATASEG:RECORDDATA CALL GET_AND_DISP_16BYTES ;Display 16 bytes of a record. INC RECBLKCOUNTER MOV AX,RECBLKCOUNTER CMP AX,LINES_PER_RECORD JB GET_AND_DISP_REC1 MOV RECBLKCOUNTER,0 MOV SI,OFFSET @DATASEG:RECORDDATA XOR CH,CH MOV CL,REMAINING_BYTES CMP CL,0 JE GET_AND_DISP_RECEND ;If no remaining bytes in block, then display ; blank line and return. CALL GET_BYTES CALL DISP_OFFSET CALL DISP_REMBYTES GET_AND_DISP_RECEND: CALL PUT_NEWLINE .POP AX,CX,SI RET .ENDP GET_AND_DISP_REC ;============================================================================= ;Procedure: GET_AND_DISP_16BYTES ; ;DESC: Reads 16 bytes from file, and displays in hex and ascii format. ; ;IN: SI points to sequence of bytes. ; ;OUT: BYTECOUNTER is updated. ;============================================================================= .PROC GET_AND_DISP_16BYTES PUSH CX MOV CX,16 CALL GET_BYTES CALL DISP_OFFSET CALL DISP_BYTES CALL DISP_ASCII_CHARS CALL PUT_NEWLINE POP CX RET .ENDP GET_AND_DISP_16BYTES ;============================================================================= ;Procedure: GET_BYTES ; ;DESC: Reads CL number of bytes from file. ; ;IN: CL contains number of bytes to read. SI points to sequence of bytes. ; BL contains the file handle. ; ;OUT: ;============================================================================= .PROC GET_BYTES .PUSH CX,SI MOV NUM_BYTES_TO_READ,CL CALL READ_H JA GET_BYTES1 JMP GET_BYTES2 GET_BYTES1: CALL CLOSE_AND_EXIT GET_BYTES2: CMP CL,NUM_BYTES_TO_READ ;If number of bytes read is less than ; expected, pointer must be at end of file. JE GET_BYTESEND GET_BYTESEND: .POP CX,SI RET .ENDP GET_BYTES ;============================================================================= ;Procedure: LAST_BYTES ; ;DESC: Reads and displays the last line of file. ; ;IN: BL contains the file handle. ; ;OUT: None ;============================================================================= .PROC LAST_BYTES .PUSH AX,BX,CX,SI MOV SI,OFFSET @DATASEG:RECORDDATA MOV CX,16 ; There should only be 1 byte left to read, but it ; doesn't hurt to attempt it at 16. The true number ; of bytes left will be returned in CL after a call ; to READ_H. CALL READ_H CALL DISP_OFFSET CALL DISP_BYTES MOV REMAINING_BYTES,CL MOV AL,CL CALL CALC_REM_SPACES MOV CL,REMAINING_SPACES CALL PUT_SPACES MOV CL,REMAINING_BYTES CALL DISP_ASCII_CHARS CALL PUT_NEWLINE .POP AX,BX,CX,SI RET .ENDP LAST_BYTES ;============================================================================= ;Procedure: DISP_BYTES ; ;DESC: Displays CL number of bytes from file, in hex format. ; ;IN: CL contains number of bytes to display. SI points to sequence of bytes. ; ;OUT: None ;============================================================================= .PROC DISP_BYTES PUSH AX MOV CURPOINTER,SI MOV POS_COUNTER,0 DISP_BYTES1: CALL DISP_HEXCHR CALL PUT_SPACE INC SI CMP POS_COUNTER,CL ;If position counter is still less than the ; number of bytes to be displayed, then JNE DISP_BYTES1 ; continue displaying. POP AX RET .ENDP DISP_BYTES ;============================================================================= ;Procedure: DISP_ASCII_CHARS ; ;DESC: Displays CL number of bytes from file, in ascii format. ; ;IN: CL contains number of bytes to display. SI points to sequence of bytes. ; ;OUT: None ;============================================================================= .PROC DISP_ASCII_CHARS PUSH AX MOV SI,CURPOINTER MOV POS_COUNTER,0 DISP_BYTES2: CALL DISP_ASCII INC SI CMP POS_COUNTER,CL JNE DISP_BYTES2 POP AX RET .ENDP DISP_ASCII_CHARS ;============================================================================= ;Procedure: DISP_ASCII ; ;DESC: Displays byte in ascii format. If ascii code of byte is less than 32, ; (20h), then display a period (.). ; ;IN: AL contains byte to display. ; ;OUT: POS_COUNTER is incremented. ;============================================================================= .PROC DISP_ASCII .PUSH AX,BX,SI LODSB CMP AL,20h JB PUT_PERIOD CALL PUT_CHR JMP DISP_ASCII1 PUT_PERIOD: MOV AL,'.' CALL PUT_CHR DISP_ASCII1: INC POS_COUNTER .POP AX,BX,SI RET .ENDP DISP_ASCII ;============================================================================= ;Procedure: DISP_REMBYTES ; ;DESC: Displays last line of record, if less than 16 bytes and more than 0. ; If the last line contains exactly 16 bytes, then it has already ; been displayed during a call to DISP_BYTES. ; ;IN: AL contains byte to display. SI points to sequence of bytes. ; ;OUT: POS_COUNTER is incremented. ;============================================================================= .PROC DISP_REMBYTES ; Display remainder of record. .PUSH AX,SI,CX MOV CURPOINTER,SI MOV POS_COUNTER,0 DISP_REMBYTES1: CALL DISP_HEXCHR CALL PUT_SPACE INC SI MOV AL,REMAINING_BYTES CMP POS_COUNTER,AL JNE DISP_REMBYTES1 MOV CL,REMAINING_SPACES CALL PUT_SPACES MOV SI,CURPOINTER MOV POS_COUNTER,0 DISP_REMBYTES2: CALL DISP_ASCII INC SI MOV AL,REMAINING_BYTES CMP POS_COUNTER,AL JNE DISP_REMBYTES2 .POP AX,SI,CX RET .ENDP DISP_REMBYTES ;============================================================================= ;Procedure: OPENDBF ; ;DESC: Opens a .DBF file. ; ;IN: DS:SI should point to the .DBF PATHNAME. ; ;OUT: BX and DBHANDLE contain the file handle. ;============================================================================= .PROC OPENDBF .PUSH AX,CX,DX,SI,DI MOV DI,OFFSET @DATASEG:DBFNAME CALL STR_LEN CALL STR_NCPY ; Now DI should point to the full path name, ; with or without the extension. MOV SI,DI ; But now SI should have the path name. MOV DI,OFFSET @DATASEG:DBEXT PUSH SI CALL STR_STRI ; Look for ".DBF" extension in path name; ; that is, look for the extension pointed ; to by DI in the string pointed to by SI. POP SI JNC OPEN_IT ; If the extension is in the filename, ; open the file. ; Otherwise,... ; Right now, SI points to the filename ; string, and DI points to the extension. XCHG SI,DI ; Make DI point to the filename and SI to ; the extension, for a call to STR_CAT. CALL STR_CAT ; Append the extension to the filename; ; that is, append the string pointed to ; by SI to the string pointed to by DI. MOV SI,DI ; Okay. Now move the offset of the path ; name back into SI. OPEN_IT: MOV AX,O_RDONLY CALL OPEN_H JC OPENDBFOUT JMP OPENDBFEND OPENDBFOUT: CALL CLOSE_AND_EXIT OPENDBFEND: MOV DBHANDLE,BX ; The file handle will generally remain in BX ; throughout the program, but store it in DBHANDLE ; just in case BX is temporarily used for ; something else. CALL GETFSIZE_H ; Get size of file at handle BX. MOV FILESIZE[0],AX ; Store it in FILESIZE. MOV FILESIZE[2],DX .POP AX,CX,DX,SI,DI RET .ENDP OPENDBF .ends .public nheap_default, fheap_default .stackseg .public stack_end ;used by START to normalize stack .label stack_end word ;must be defined past entire stack .label nheap_default word ;used by the near heap .label fheap_default word ;used by the far heap .ends end start ;specify START as starting address