After creating the shared library that defines the new tag, you load the library into Web Server in the usual way for NSAPI plug-ins. That is, add the following directives to the configuration file magnus.conf:
Add an Init directive whose fn parameter is load-modules and whose shlib parameter is the shared library to load. For example, if you compiled your tag into the shared object install_dir /hello.so, it would be:
Init funcs="mytag,mytag_init" shlib="install_dir/hello.so" fn="load-modules"
Add another Init directive whose fn parameter is the initialization function in the shared library that uses shtml_add_tag to register the tag. For example:
Init fn="mytag_init"