How to access any CDF previous version
--------------------------------------

1. On Linux/Unix

   Assume the previous version had been built. Otherwise, download the source
   and build it.

   Execute the definitions shell to set up proper environment variables and
   aliases from a previous version in a terminal session:

   From Bourne shell:

    $ . <path>/bin/definitions.B
   
   where <path> is the base folder of a previous CDF version, e.g., 
   cdf39_0-dist.

   From C-shell or tcsh:

    $ source <path>/bin/definitions.C

   Form Korn shell:

    $ . <path>/bin/definitions.K

   Once, all environment variables and aliases are set, the dynamically loaded
   libraries used in Java-CDF APIs, and CDF tools, e.g., cdfexport, cdfedit,
   etc, will use the designated CDF version during the terminal session.

2. Mac OS X

   Assume the CDF pre-built package had been downloaded and installed.
   Otherwise, go to the CDF home page to download it, or follow the
   instructions in Linux/Unix to build it from the source.
 
   Execute the definitions shell to set up proper environment variables and
   aliases from a previous version in a terminal session:

   From Bourne shell:

    $ . <path>/bin/definitions.B
   
   where <path> is the base folder of a previous CDF version, e.g., 
   /Applications/cdf/cdf39_0-dist.

   From C-shell or tcsh:

    $ source <path>/bin/definitions.C

   Form Korn shell:

    $ . <path>/bin/definitions.K

   Once, all environment variables and aliases are set, the dynamically loaded
   libraries used in Java-CDF APIs, and CDF tools, e.g., cdfexport, cdfedit,
   etc, will use the designated CDF version during the terminal session.

   If you only want to run the Java-based CDF tools, CDFToolsDriver, you don't
   need to run the aforementioned definitions shell. Double-click
   <path>/CDFToolsDriver.app from finder will run the tools of that version.
   
3. On Windows

   Assume the CDF pre-built package had been downloaded and installed. 
   Otherwise, go to CDF home page to download it.

   Bring up a command-line terminal, then go to the directory <path> that the
   intended CDF version is located, e.g.  c:\CDF_distribution\cdf39_0-dist, 
   to check if the batch file: setenv.bat, exists.

   If it does, run setenv.bat to set up the environment variables.
   If it does not, then copy the following code to setenv.bat

     @echo off
     set mydir=%~dp0
     set CDF_BASE=%mydir%
     set CDF_HELP=%mydir%help
     set CLASSPATH=%mydir%CDFToolsDriver.jar;%mydir%lib\cdfjava.jar;%mydir%cdfml\cdfml.jar;
     set PATH=%mydir%;%mydir%bin;%mydir%lib;%PATH%
     set TERMINFO=%mydir%lib\terminfo

   If the previous CDF version is for V3.6.0 or later, add one more line to
   the batch file:

     set CDF_LEAPSECONDSTABLE=%mydir%CDFLeapSeconds.txt

   Once setenv.bat is built, run it.

   All dynamically loaded libraries used in Java-CDF APIs, and CDF tools,
   e.g., cdfexport, cdfedit, etc, will point to the designated CDF version
   during the terminal session.

4. OpenVMS

   Execute the definitions command to set up logical names and symbols from
   a previous version in a terminal session: set the current directory to
   the selected CDF version, e.g., [cdf39_0-dist]. Run the command:
   @definitions.

   Once logical names and symbols are set, CDF tools, e.g., cdfexport, cdfedit,
   etc, will point to the designated CDF version during the terminal session.


