The link-editors support a number of environment variables that begin with the characters LD_, for example LD_LIBRARY_PATH. Each environment variable can exist in its generic form, or can be specified with a _32 or _64 suffix, for example LD_LIBRARY_PATH_64. This suffix makes the environment variable specific, respectively, to 32–bit or 64–bit processes. This suffix also overrides any generic, non-suffixed, version of the environment variable that might be in effect.
Prior to the Solaris 10 release, the link-editors ignored environment variables that were specified without a value. Therefore, in the following example, the generic environment variable setting, /opt/lib, would have been used to search for the dependencies of the 32–bit application prog.
$ LD_LIBRARY_PATH=/opt/lib LD_LIBRARY_PATH_32= prog
With the Solaris 10 release, environment variables specified without a value, that have a _32 or _64 suffix, are processed. These environment variables effectively cancel any associated generic environment variable setting. Thus in the previous example, /opt/lib will not be used to search for the dependencies of the 32–bit application prog.