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How to build and install the Secure Socket Layer (SSL) library

If you want to run an OPeNDAP-enabled version of NCL, then you may first need to install the SSL library.

If you already have the OPeNDAP-enabled version of NCL, then you can quickly test if you need to install the SSL library by running ncl at the UNIX command line:

ncl

ncl 0> quit

If you get an error message that looks like this:

  ncl: error while loading shared libraries: libssl.so.4: cannot open shared
  object file: No such file or directory

then this means that you either need to install the SSL library, or you need to talk to your system administrator to find out where it resides. If it is already installed on your system, then you may need to setenv your LD_LIBRARY_PATH environment variable to the location of this library.

Otherwise, if you think you need to build SSL, it should be pretty straightforward. Here are the basic instructions:

• Go to http://www.openssl.org/source/

• Download the openssl-x.y.z.tar.gz file that is marked "LATEST". If possible, you should try to install the library to a directory like /usr/lib or /lib so that the NCL binary can find it. Otherwise, you may need to setenv the LD_LIBRARY_PATH environment variable to the location of your SSL library.

• There are a few options when configuring the build, so be sure to have a look at the file INSTALL in the source distribution. You can build a non-shared version of the libraries but it's typically best to leave it as a shared library. Just FYI: on our build/test systems, SSL is system-installed and we use those libraries.