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 HWND
   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

Result:

 Found C:\Windows\notepad.exe
 Found C:\Windows\System32\notepad.exe
 Found C:\Windows\SysWOW64\notepad.exe
 Found C:\Windows\WinSxS\amd64_microsoft-windows-notepad_31bf3856ad364e35_10.0.19041.117_none_4d353cf1ceb5d6d2\f\notepad.exe
 Found C:\Windows\WinSxS\amd64_microsoft-windows-notepad_31bf3856ad364e35_10.0.19041.117_none_4d353cf1ceb5d6d2\notepad.exe
 Found C:\Windows\WinSxS\amd64_microsoft-windows-notepad_31bf3856ad364e35_10.0.19041.117_none_4d353cf1ceb5d6d2\r\notepad.exe
 Found C:\Windows\WinSxS\amd64_microsoft-windows-notepad_31bf3856ad364e35_10.0.19041.1_none_250b9aff0f5d41ee\notepad.exe
 Found C:\Windows\WinSxS\wow64_microsoft-windows-notepad_31bf3856ad364e35_10.0.19041.1_none_2f60455143be03e9\notepad.exe