Microsoft KB Archive/148689

= How to Parse Config.fpw Programmatically =

Article ID: 148689

Article Last Modified on 9/30/2003

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APPLIES TO


 * Microsoft Visual FoxPro 3.0 Standard Edition
 * Microsoft Visual FoxPro 3.0b Standard Edition

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This article was previously published under Q148689



SUMMARY
This article shows by example how to parse through a text file programmatically. This example uses Config.fpw. The code searches for a specific entry, and then it modifies the entry if it is found or adds it if not found.

You might want to use this technique in distributed applications, for example, to control the operating environment.



MORE INFORMATION
This code example checks to determine if the Visual FoxPro system variable MVCOUNT is less than 2000. If follows this process:

 Open or Create the Config.fpw file as applicable, Search through the Config.fpw file for the MVCOUNT= entry.  If it finds an entry, it modifies it to read MVCOUNT=2000. If it doesn't find an entry, it creates one.  Write the modified file contents back to disk, and close the file.</ol>

Code Sample
* Parsefpw.prg cNewLine  = "MVCOUNT=2000"+CHR(13)      && This is the line to change/add nUpdateStat = 0                         && Use to determine which message cVFPConfigLoc = SYS(2019) nFileHand  = FOPEN(cVFPConfigLoc, 2)    && open with read/write privileges IF nFileHand == -1                      && Can't find Config.fpw nFileHand = FCREATE(cVFPConfigLoc, 0) && Create an Config.fpw IF nFileHand == -1                    && Can't create Config.fpw = FCLOSE(nFileHand) nUpdateStat = 1                     && Not existing, Cannot Create ELSE = FWRITE(nFileHand, cNewLine) = FCLOSE(nFileHand) nUpdateStat = 2                     && Not existing, Did Create ENDIF ELSE filesize = FSEEK(nFileHand, 0, 2) = FSEEK(nFileHand, 0, 0)              && position file pointer to BOF contents = FREAD(nFileHand, filesize) spos = RAT("MVCOUNT", UPPER(contents)) && from right to find last MVCOUNT
 * To make this backward compatible to FoxPro 2.x, replace the MESSAGEBOX
 * functions with WAIT WINDOWs
 * functions with WAIT WINDOWs

IF spos <> 0                          && Contains "MVCOUNT" entry * len = length (for example, len=20+1=21 for "MVCOUNT = 30 ") * len = AT(CHR(13)+CHR(10), SUBSTR(contents, spos)) - 1 && w/o CR & LF   len = AT(CHR(13)+CHR(10), SUBSTR(contents, spos)) + 1 && with CR & LF    IF LEN = 0 LEN = LEN(SUBSTR(contents, spos)) ENDIF ELSE                                  && "MVCOUNT" Not there, append it    LEN = AT(CHR(26), contents)          && CHR(26) = Escape = EOF marker IF LEN <> 0 contents = LEFT(contents, LEN - 1) LEN = 0 ENDIF spos = RAT(CHR(13)+CHR(10), contents, ;   IIF(RIGHT(contents, 2) <> CHR(13)+CHR(10), 1, 2)) spos = spos + IIF(spos = 0, 1, 2) ENDIF contents = STUFF(contents, spos, LEN, cNewLine) = FSEEK(nFileHand, 0, 0) = FWRITE(nFileHand, contents) = FCHSIZE(nFileHand, LEN(contents)) = FCLOSE(nFileHand) nUpdateStat = 3                          && Did exist, Modified ENDIF ?? CHR(7) cMsg1 = "A file named Config.fpw must exist in <YourApp>"+CHR(13); +"startup directory. This file must contain an MVCOUNT=2000"+CHR(13); +"statement in order for the <YourApp> application to operate"+CHR(13); +"correctly."+CHR(13)+CHR(13) DO CASE CASE nUpdateStat = 1 && Not existing, Cannot Create =MESSAGEBOX(cMsg1+;   +"The computer system could not find this file nor could it"+CHR(13);    +"create one. Until one exists, <YourApp> cannot be used.",0) CASE nUpdateStat = 2 && Not existing, Did Create =MESSAGEBOX(cMsg1+;   +"The <YourApp> startup directory did not include this"+CHR(13);    +"file so one was created for you. The new Config.fpw file"+CHR(13);    +"contains all the required settings for the <YourApp>"+CHR(13);    +"application to run."+CHR(13)+CHR(13);    +"In order to activate this statement you need to RESTART the"+CHR(13);    +"<YourApp> application.",0) CASE nUpdateStat = 3 && Did exist, Modified =MESSAGEBOX(cMsg1+;   +"Your existing Config.fpw file has now been modified to contain"+CHR(13);    +"an MVCOUNT=2000 statement. To activate this statement you need"+CHR(13);    +"to RESTART the <YourApp> application.",0) ENDCASE

Additional query words: VFoxWin

Keywords: kbcode KB148689

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