Q121441: Code Sample to Find Application Path Using File Extension

Article: Q121441
Product(s): Microsoft FoxPro
Version(s): 2.5x 2.60 2.60a 3.00
Operating System(s): 
Keyword(s): kbcode
Last Modified: 21-AUG-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
- Microsoft FoxPro for Windows, versions 2.5x, 2.6, 2.6a 
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SUMMARY
=======

If you know the file extension of a file type that an application uses, you can
quickly determine the full path of that application by reading the [EXTENSIONS]
section of the WIN.INI file (the Windows 3.x initialization file). To do this
programmatically from FoxPro, you can use the FOXTOOLS.FLL library to make a
call to the Windows API GetPrivateProfileString() function, as the code example
below demonstrates.

NOTE: For backward compatibility, Visual FoxPro still supports FOXTOOLS.FLL
(included in earlier FoxPro versions), the Visual FoxPro API library that allows
calls to 16-bit .DLL functions. However, in Visual FoxPro, the DECLARE command
is the preferred method for calling .DLL functions.

MORE INFORMATION
================

NOTE: This example only works with Windows version 3.x (16-bit versions), which
use the WIN.INI file. Windows NT and Windows 95 use the Registry instead of
WIN.INI.

When you run this code, you will be prompted to enter the extension. For example,
enter a file extension such as "XLS" (without the quotation marks) and press
ENTER. If Microsoft Excel is installed, the full path to Microsoft Excel will be
returned.

     SET LIBRARY TO SYS(2004)+"foxtools"
     @ 1,1 GET ext DEFAULT "     " SAY "Enter the extension: "
     READ
     ext=ALLTRIM(ext)
     IF LEN(ext)=0
        RETURN
     ENDIF
     mpath=REPLICATE(CHR(0),256)

     * Register and call the Windows API function.

     mregister=regfn("GetPrivateProfileString","CCC@CIC","I")
     mcall=callfn(mregister,"Extensions",ext,"",@mpath,256,"WIN.INI")

     mpath=ALLTRIM(mpath)
     CNT=OCCURS('\',mpath)  && find the last backslash in the path
     IF CNT=0
        ? CHR(7)
        WAIT WINDOW "File Extension Not Found"  && in the WIN.INI file
        RETURN
     ENDIF
     x=AT('\',mpath,CNT)  && find the position of the last backslash
     mpath=SUBSTR(mpath,1,x-1)  && extract just the path
     @ 2,1 SAY "The path to the executable is " + mpath

Additional query words: VFoxWin FoxWin 2.50 2.50a 2.50b 2.50c

======================================================================
Keywords          : kbcode 
Technology        : kbVFPsearch kbAudDeveloper kbFoxproSearch kbFoxPro260 kbFoxPro260a kbVFP300
Version           : 2.5x 2.60 2.60a 3.00

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