How To Check for a Writeable Drive Under Windows NT

MORE INFORMATION

Sample Code

   *-- Code begins here.
   CLEAR

   *-- Check if floppy drive a: is available for writing
   *-- and print the results.  Try this twice, once with
   *-- a write-protected floppy and again with a floppy
   *-- that is not write-protected.
   ? CheckMediaWrite("a:")

   *-----------------------------------------------------------------
   *- Function:    CheckMediaWrite
   *- Summary:     Checks if the passed drive is available for writing.
   *- Parameters:  lsDrive - The drive to check.
   *- Returns:     -1 If drive cannot be written to.
   *- Example:     liReturn = CheckWrite("a:")
   *-----------------------------------------------------------------
   FUNCTION CheckMediaWrite()
   PARAMETERS lsDrive

   *-- Defines from Winbase.h
   #DEFINE SEM_FAILCRITICALERRORS      0x0001
   #DEFINE SEM_NOGPFAULTERRORBOX       0x0002
   #DEFINE SEM_NOALIGNMENTFAULTEXCEPT  0x0004
   #DEFINE SEM_NOOPENFILEERRORBOX      0x8000

   *-- Check that the parameter is in the correct format.
   IF SUBSTR(lsDrive, 2, 1) <> ":" OR ;
     (ASC(UPPER(SUBSTR(lsDrive, 1, 1))) < 65 OR ;
     ASC(UPPER(SUBSTR(lsDrive, 1, 1))) > 90)
       =MESSAGEBOX("Drive must be in the format <drive letter>:", ;
         0, "Error")
       RETURN -1
   ENDIF

   *-- SetErrorMode determines whether the system handles
   *-- serious errors or whether the program handles them.
   DECLARE INTEGER SetErrorMode IN win32api INTEGER

   *-- SetErrorMode returns to what the flags were last set.
   *-- You need to store this in lnResult so that you can set them
   *-- back the way they were before calling SetErrorMode.
   *-- Failure to do so can produce unpredictable results
   *-- when encountering future errors.  SetErrorMode only
   *-- applies to the current process and therefore only affects
   *-- the FoxPro program that called SetErrorMode.
   lnResult = SetErrorMode(SEM_FAILCRITICALERRORS)

   hFile = FCREATE(lsDrive + "\tmp.txt")
   IF hFile <> -1
       FCLOSE(hFile)
       ERASE(lsDrive + "\tmp.txt")
   ENDIF

   *-- Put things back the way you found them.
   lnResult = SetErrorMode(lnResult)

   RETURN hFile
   *-- Code ends here.