BBC BASIC Programmers' Reference

by Jon Ripley, August 2007

The FNtempfile function creates and returns the name of a unique file in the current temporary directory. You should ensure that you delete this file when you no longer require it.

      file$ = FNtempfile
      REM ...
      SYS "DeleteFile", file$

The FNtempdir function creates and returns the name of a unique directory in the current temporary directory. You should ensure that you delete this directory when you no longer require it.

      dir$ = FNtempdir
      REM ...
      SYS "RemoveDirectory", dir$

The “RemoveDirectory” call requires that the directory to be deleted is empty. To delete a non-empty directory use the PROCremovedirectory function as demonstrated:

      dir$ = FNtempdir
      REM ...
      PROCremovedirectory(dir$)

The code for the FNtempfile, FNtempdir and PROCremovedirectory functions referenced in this article are listed below:

      DEF FNtempfile
      LOCAL T%
      DIM T% LOCAL 255
      SYS "GetTempPath", 256, T%
      SYS "GetTempFileName", $$T%, "tmp", 0, T%
      = $$T%

      DEF FNtempdir
      LOCAL T%
      DIM T% LOCAL 255
      SYS "GetTempPath", 256, T%
      SYS "GetTempFileName", $$T%, "tmp", 0, T%
      SYS "DeleteFile", $$T%
      SYS "CreateDirectory", $$T%, 0
      IF $$T% > "" $$T% += "\"
      = $$T%

      DEF PROCremovedirectory(D$)
      IF D$ = "" THEN ENDPROC
      LOCAL shfo{}
      DIM shfo{hWnd%, wFunc%, pFrom%, pTo%, fFlags%, fAborted%, hNameMaps%, sProgress%}
      IF RIGHT$(D$,1) = "\" THEN D$ = LEFT$(D$)
      D$ += CHR$0 + CHR$0
      shfo.hWnd% = @hwnd%
      shfo.wFunc% = 3
      shfo.pFrom% = !^D$
      shfo.fFlags% = 20
      SYS "SHFileOperation", shfo{}
      ENDPROC

The string “tmp” passed to “GetTempFileName” is a prefix for the temporary file name which you may change to any three character string, perhaps to be distinctive to your application.