                             VERY IMPORTANT
                             --------------

     Installation of this library must be accompanied by making an environment variable which contains a conjoined string of the standard 12 file modes as the code needed by the operating system to open/create a file for particular kinds of operations.   The variable must be named SATHER_MODES.

     A typical contents for a Unix operating system would be

          w=wb=r=rb=a=ab=w+=w+b=r+=r+b=a+=a+b

where an equals mark is used to separate the substrings.  See the FileSys class FILE_MODES for the semantics attached to each code string.