How to Use Wildcards in a String Search Routine

ID: Q146221

3.00 3.00b WINDOWS

 kbhowto

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 3.0 and 3.0b

SUMMARY

FoxPro includes several functions, such as AT(), that you can use to determine if a string is contained within another string. However, no native function exists that will use wildcards in the string to be searched for in the larger string. This article shows by example how to search for a string containing wildcards within a larger string.

MORE INFORMATION

Sample Code

FUNCTION wcardfind PARAMETER srchstr, wildcard, longstr

STORE 0    TO ifoundat

STORE LEN(longstr) TO ilongstrlen STORE LEN(ALLT(srchstr)) TO isrchstrlen STORE ilongstrlen - isrchstrlen TO ilastoffset STORE isrchstrlen - LEN(ALLT(STRTRAN(srchstr, wildcard, ""))) ;

   TO inumwcards

STORE .F. TO lfound

STORE 0   TO isrchoffset

STORE (ilongstrlen > isrchstrlen) AND ;

   (LEN(wildcard)=1) AND (isrchstrlen>0) TO ok

DO WHILE (! isrchoffset > ilastoffset) AND (! lfound) AND ok

   STORE 0 TO imatch
   FOR LOOP = 1 TO isrchstrlen
      IF ASC(SUBSTR(srchstr,LOOP,1)) = ;
           ASC(SUBSTR(longstr,LOOP+isrchoffset,1))
         imatch=imatch+1
      ENDIF
   ENDFOR
   IF imatch+inumwcards = isrchstrlen
      lfound = .T.
      ifoundat = isrchoffset+1
   ELSE
      isrchoffset=isrchoffset+1
   ENDIF

ENDDO RETURN IIF(lfound,ifoundat,0)

Testing the Function

Place the following code before the above function in a program file to test the function. The value returned in the wait window should be 4:

   x1="d?f"
   x2="?"
   x3="abcdefgh"
   xresult=wcardfind(x1,x2,x3)
   wait wind str(xresult)

Additional reference words: 3.00 3.00b VFoxWin KBCategory: kbhowto KBSubcategory: FxprgGeneral

Keywords          : kbcode FxprgGeneral 
Version           : 3.00 3.00b
Platform          : WINDOWS