Arguments

 

file_spec

   A character string containing a valid file specification.
 

a_mode

   The access mode indicator. Use one of the following character
   strings: "r", "w", "a", "r+", "w+", "rb", "r+b", "rb+", "wb",
   "w+b", "wb+", "ab", "a+b", "ab+", or "a+".

   These access modes have the following effects:

   o  "r" opens an existing file for reading.

   o  "w" creates a new file, if necessary, and opens the file for
      writing. If the file exists, it creates a new file with the
      same name and a higher version number.

   o  "a" opens the file for append access. An existing file is
      positioned at the end-of-file, and data is written there. If
      the file does not exist, the C RTL creates it.

   The update access modes allow a file to be opened for both
   reading and writing. When used with existing files, "r+" and
   "a+" differ only in the initial positioning within the file. The
   modes are:

   o  "r+" opens an existing file for read update access. It is
      opened for reading, positioned first at the beginning-of-file,
      but writing is also allowed.

   o  "w+" opens a new file for write update access.

   o  "a+" opens a file for append update access. The file is first
      positioned at the end-of-file (writing). If the file does not
      exist, the C RTL creates it.

   o  "b" means binary access mode. In this case, no conversion of
      carriage-control information is attempted.
 

 . . .

   Optional file attribute arguments. The file attribute arguments
   are the same as those used in the creat function. For more
   information, see the creat function.