Arguments

 

directory

   A pointer to the pathname of the directory where you want to
   create a file.
 

prefix

   A pointer to an initial character sequence of the filename. The
   prefix argument can be null, or it can point to a string of up
   to five characters used as the first characters of the temporary
   filename.
 

 . . .

   An optional argument that can be either 1 or 0. If you specify 1,
   tempnam returns the file specification in OpenVMS format. If you
   specify 0, tempnam returns the file specification in UNIX style
   format.