Recursive Functions

Recursive User-Defined Functions

Can BCX handle recursive functions?

No problem! Here's a popular example.

 ' Example function call usage 1
 'SearchForFiles("C:\", "win.ini")
  
 ' Example function call usage 2
 SearchForFiles("C:\Windows", "Notepad.exe")
  
 SUB SearchForFiles(startPath$, FileToFind$)
   DIM RAW fPath$, wildpath$, fName$, fPathName$
   DIM RAW hfind AS HANDLE
   DIM RAW WFD AS WIN32_FIND_DATA
   DIM RAW found AS BOOLean
   DIM RAW filename$    
  
   ' Prepare filename$ for comparison with found file names
   filename$ = LCASE$(FileToFind$)
  
   ' Make a local copy of the search path
   fPath$ = startPath$
  
   ' Make sure search path ends with a backslash
   IF RIGHT$(fPath$, 1) <> "\" THEN fPath$ = fPath$ + "\"
  
   ' We want to find all files and folders so we'll
   ' add a wildcard asterisk to the search path
   wildpath$ = fPath$ + "*"
  
   ' Ask Windows API for first file or folder
   ' in our search path
   hfind = FindFirstFile(wildpath$, &WFD)
  
   ' Did we get one?
   IF hfind != INVALID_HANDLE_VALUE THEN
     found = TRUE
   ELSE
     found = FALSE
   END IF
 
   DO WHILE found
     ' Get the name of the file or folder
     ' from the WIN32_FIND_DATA structure
     fName$ = WFD.cFileName
  
     ' Add the file or folder name to the search path
     fPathName$ = fPath$ + fName$
  
     IF fName$ != "." THEN   ' ignore "current folder"
       IF fName$ != ".." THEN ' ignore "parent folder"
  
         ' Did we find a file or a folder?
         IF(WFD.dwFileAttributes BAND FILE_ATTRIBUTE_DIRECTORY) THEN
  
           ' Found a folder so look for our target
           ' file in that folder
           SearchForFiles(fPathName$, filename$)
  
           ' Found a file so does it match our target?
         ELSEIF LCASE$(fName$) = filename$ THEN
  
           ' Code here could call another routine,
           ' add the found file to a listbox,
           ' or whatever. We'll just display it's
           ' full path and name in a message box
           PRINT "Found ", fPathName$
         ELSE
  
           ' File searching can be a lengthy process
           ' so give other processes a chance to do
           ' whatever they need to do
           DOEVENTS
  
         END IF
       END IF
     END IF
  
     ' Ask Windows API for the next file or
     ' folder in our search path
     found = FindNextFile(hfind, &WFD)
   LOOP
  
   ' Tell Windows API we've finished searching
   FindClose(hfind)
  
 END SUB