The ENCODE and DECODE statements transfer data between variables or
  arrays in internal storage.  The ENCODE statement translates data
  from internal (binary) form to character form.  Inversely, the
  DECODE statement translates data from character to internal form.
  These statements are comparable to using internal files in
  formatted sequential WRITE and READ statements, respectively.
  Statement format:

     ENCODE (c,f,b [,IOSTAT=ios] [,ERR=s]) [list]
     DECODE (c,f,b [,IOSTAT=ios] [,ERR=s]) [list]

     c      Is an integer expression.  In the ENCODE statement,
            "c" is the number of characters (in bytes) to be
            translated to character form.  In the DECODE statement,
            "c" is the number of characters to be translated to
            internal form.

     f      Is a format identifier.  An error occurs if more than
            one record is specified.

     b      Is a scalar or array reference. If b is an array
            reference, its elements are processed in the
            order of subscript progression. The data type of "b"
            determines the number of characters that ENCODE or
            DECODE can process.

            In the ENCODE statement, "b" receives the characters
            after translation to external form.  If less than "c"
            characters are received, the remaining character
            positions are filled with blank characters.

            In the DECODE statement, "b" contains the characters
            to be translated to internal form.

     ios    Is a scalar integer variable that is defined
            as a positive integer if an error occurs, and zero
            if no error occurs.

     s      Is the label of an executable statement.

     list   Is an I/O list.

            In the ENCODE statement, the "list" contains the data
            to be translated to character form.  In the DECODE
            statement, the "list" receives the data after
            translation to internal form.

            The interaction between the format specifier and the
            I/O list is the same as for a formatted I/O statement.