This section describes the functions in the various networking libraries, including the Lightweight Directory Access Protocol (LDAP) library ( libldap), the network service library (libnsl), the resolver library (libresolv), the remote procedure call libraries (librpcsvc and librpcsoc), the sockets library (libsocket), the X/Open Federated Naming (XFN) library (libxfn), and the X/Open network service library (libxnet). Readers of this section should be familiar with C programming language constructs.