'=========================================================================== ' Subject: GET PROGRAM STARTUP LOCATION Date: 04-16-99 (15:55) ' Author: Dan Autery Code: ASIC ' Origin: Autery@aol.com Packet: ASIC.ABC '=========================================================================== REM *** PROGLOC.ASI -- Get Program Startup Location REM *** Donated to the Public Domain by Dan Autery (autery@aol.com) REM *** REM *** Code based on FILESPEC.BAS, by Ronny Ong REM *** REM *** The following snippets show two routines for getting the startup REM *** directory of your EXE program. This information is handy for a REM *** number of reasons. In the examples below, the routines return REM *** the path name of the data file where this program's user- REM *** preferences are stored. This allows the program to always find REM *** and/or write to the correct file. REM *** REM *** The first routine is a plain, ASIC 5.0, adaptation of FILESPEC.BAS REM *** The second routine is an Assembly level version of the above. REM *** You'll find that the latter compiles to a MUCH smaller size than REM *** the former (and is faster as well). ;) REM *** First, find the program's DATA segment: This GETREGS routine REM *** _must_ be placed at the VERY beginning of your ASIC program REM *** (immediately after any REM, DIM, or DATA statements). Placing it REM *** later in your code could have potentially harmful results.. GETREGS(na,na,na,na,na,na,na,DS,na) Dseg=DS REM 'Gets the location (directory) of this program and puts it in progname$ progloc: AX=&Hex6200 REM ** Calls DOS interrupt 21 (hex), service 6200 (hex) (GET PSP) Int86(&hex21,AX,BX,Na,Na,Na,Na,Na,Na,Na) DEFSEG=BX num=PEEK(&hex2D) AB&=num AB&=AB&*256& num=PEEK(&hex2C) AT&=num AB&=AB&+AT& DEFSEG=AB& REM ** The following assembles the complete path & name: n=1 progname$="" value=0 WHILE n=1 num=PEEK(value) value=value+1 IF num=0 THEN num=PEEK(value) IF num=0 THEN value=value+3 num=PEEK(value) WHILE num<>0 value=value+1 key$=CHR$(num) progname$=progname$+key$ num=PEEK(value) WEND n=0 ENDIF ENDIF IF value<0 THEN n=0 ENDIF WEND REM ** At this point, progname$ contains the path\name of your program REM ** Since ASIC strings can only be 79 bytes, though, let's double-check REM ** to make sure our progname$ is valid: key$=FIND FIRST(progname$,0) IF ERROR=0 THEN n=LEN(progname$) ENDIF REM ** This next routine finds the length of our string, minus the name REM ** of the EXE file (to allow us to extract the directory name). num=0 IF n>0 THEN WHILE n>0 n=n-1 key$=MID$(progname$,n,1) IF key$="\" THEN num=n n=n-1 key$=MID$(progname$,n,1) REM ** While the following ~might~ not be necessary, it's here to trap REM ** any odd startup strings. For example, if a person were to start REM ** your program from one directory up by typing "..\prog.exe", REM ** progname$ could be: "c:\mydir\..\prog.exe". REM ** If found, this adjusts the string length to compensate. IF key$<>"." THEN n=0 ENDIF ENDIF WEND ENDIF REM ** Again, we're checking the length of our string because of the REM ** ASIC '79 character' string limitation (grrr!). Since the DAT file REM ** name is 8 characters, the path can be no longer than 71 chars. IF num>71 THEN num=0 ENDIF progname$=LEFT$(progname$,num) progname$=progname$+"prefs.dat" DEFSEG=-1 RETURN REM 'This is the Assembly level (machine language) version of the above. REM 'The actual Assembly commands used to create this are shown below. progloc_asm: DI=VARPTR(progname$) ES=Dseg CODE 30,6 SETREGS(na,na,na,na,DI,na,na,na,ES) CODE 6,87,49,192,170,180,98,205,33,142,219,190,44,0,173,142,192,6,31,49 CODE 255,185,0,128,49,192,242,174,117,54,174,117,249,71,71,185,79,0,137,203 CODE 87,94,242,174,117,38,41,203,137,217,95,7,6,87,243,164,253,137,217,176 CODE 92,242,174,87,79,184,46,46,175,95,117,6,176,92,242,174,242,174,252 CODE 71,71,176,0,170,95,7,7,31 REM 'progname$ now contains the complete path (minus the exe name) REM 'of your program. num=LEN(progname$) IF num>71 THEN progname$="" ENDIF progname$=progname$+"prefs.dat" RETURN REM QB CALL ABS CODES ASM CODES ASIC CODES NOTES REM (&H1E) ' PUSH DS 30 REM (&H6) ' PUSH ES 6 REM *** USE SETREGS(na,na,na,na,DI,na,na,na,ES) HERE *** REM (&H6) ' PUSH ES 6 save (new) ES REM (&H57) ' PUSH DI 87 save (new) DI REM (&H31)+(&HC0) ' XOR AX,AX 49,192 AX=0 REM (&HAA) ' STOSB 170 nul progname$ string REM (&HB4)+(&H62) ' MOV AH,62 180,98 AX=6200h REM (&HCD)+(&H21) ' INT 21 205,33 call the interrupt REM (&H8E)+(&HDB) ' MOV DS,BX 142,219 DS=PSP REM (&HBE)+(&H2C)+(&H0) ' MOV SI,002C 190,44,0 SI=2Ch REM (&HAD) ' LODSW 173 Get the entire word REM (&H8E)+(&HC0) ' MOV ES,AX 142,192 and put it into ES REM (&H6) ' PUSH ES 6 Copy ES to DS (for later) REM (&H1F) ' POP DS 31 ..via the stack REM (&H31)+(&HFF) ' XOR DI,DI 49,255 DI=0 REM (&HB9)+(&H0)+(&H80) ' MOV CX,8000 185,0,128 CX=32K (max env size) REM (&H31)+(&HC0) ' XOR AX,AX 49,192 AX=0 REM (&HF2) ' Again: REPNZ 242 repeat while AL is REM (&HAE) ' SCASB 174 NOT equal to ES:DI REM (&H75)+(&H36) ' JNZ Exit 117,54 If No match, then exit REM (&HAE) ' SCASB 174 Is next byte zero? REM (&H75)+(&HF9) ' JNZ Again 117,249 No? Repeat search. REM (&H47) ' INC DI 71 skip two bytes REM (&H47) ' INC DI 71 after the '00' REM (&HB9)+(&H4F)+(&H0) ' MOV CX,004F 185,79,0 Max string len=79 REM (&H89)+(&HCB) ' MOV BX,CX 137,203 Copy to BX for later REM (&H57) ' PUSH DI 87 Copy DI to SI REM (&H5E) ' POP SI 94 ..via the stack REM (&HF2) ' REPNZ 242 Searching for nul terminator REM (&HAE) ' SCASB 174 Do the search REM (&H75)+(&H26) ' JNZ Exit 117,38 No match? Then exit. REM (&H29)+(&HCB) ' SUB BX,CX 41,203 Get our string size REM (&H89)+(&HD9) ' MOV CX,BX 137,217 And put it in CX REM (&H5F) ' POP DI 95 Restore string pointer REM (&H7) ' POP ES 7 And program segment REM (&H6) ' PUSH ES 6 Save 'em (needed, since REM (&H57) ' PUSH DI 87 we're popping them later) REM (&HF3) ' REPZ 243 Copy 'CX' bytes REM (&HA4) ' MOVSB 164 From DS:SI to ES:DI REM (&HFD) ' STD 253 Set direction flag for backward scan REM (&H89)+(&HD9) ' MOV CX,BX 137,217 Restore string size REM (&HB0)+(&H5C) ' MOV AL,5C 176,92 Looking for "\" REM (&HF2) ' REPNZ 242 Repeat while ES:DI REM (&HAE) ' SCASB 174 is NOT equal to AL REM (&H57) ' PUSH DI 87 Save DI REM (&H4F) ' DEC DI 79 Odd, but needed REM (&HB8)+(&H2E)+(&H2E)' MOV AX,2E2E 184,46,46 Looking for ".." REM (&HAF) ' SCASW 175 in the next word REM (&H5F) ' POP DI 95 Restore DI (w/out changing flags) REM (&H75)+(&H6) ' JNZ Over 117,6 No match? Jump over: REM (&HB0)+(&H5C) ' MOV AL,5C 176,92 Look for next '\' REM (&HF2) ' REPNZ 242 Do twice: Once to REM (&HAE) ' SCASB 174 remove "..", and once REM (&HF2) ' REPNZ 242 to remove extra dir REM (&HAE) ' SCASB 174 name that ".." adds REM (&HFC) ' Over: CLD 252 ALWAYS Clear dir flag if set REM (&H47) ' INC DI 71 SCASB left us one byte REM (&H47) ' INC DI 71 before the '\', but we REM (&HB0)+(&H0) ' MOV AL,00 176,0 need one byte after.. REM (&HAA) ' STOSB 170 write end-of-string nul REM (&H5F) ' Exit: POP DI 95 restore the stack REM (&H7) ' POP ES 7 " REM (&H7) ' POP ES 7 " REM (&H1F) ' POP DS 31 "