\section{/usr}
\begin{frame}
   {/usr}

   \begin{table}[H]
      \caption{Directories Under \texttt{\textbf{/usr}}}
      \vspace{-15pt}
   \end{table}

   \small{\begin{tcolorbox}[unbreakable,tabularx={p{0.15\textwidth}|X}]
         \filelink{/usr/bin}     & Non-essential command binaries                        \\ \hline
         \filelink{/usr/etc}     & Non-essential configuration files (usually empty)     \\ \hline
         \filelink{/usr/games  } & Game data                                             \\ \hline
         \filelink{/usr/include} & Header files used to compile applications.            \\ \hline
         \filelink{/usr/lib    } & Library files                                         \\ \hline
         \filelink{/usr/lib64  } & Library files for 64-bit                              \\ \hline
         \filelink{/usr/local  } & Third-level hierarchy (for machine local files)       \\ \hline
         \filelink{/usr/sbin   } & Non-essential system binaries                         \\ \hline
         \filelink{/usr/share  } & Read-only architecture independent files              \\ \hline
         \filelink{/usr/src    } & Source code and headers for the \textbf{Linux} kernel \\ \hline
         \filelink{/usr/tmp    } & Secondary temporary directory
      \end{tcolorbox}}

\end{frame}

\cprotect\note{

   The \filelink{/usr} directory can be thought of as a
   \textbf{secondary hierarchy}; it is used for files
   which are not needed for system booting.  Indeed,
   \filelink{/usr} need not reside in the same
   partition as the root directory, and can be shared
   among hosts using the same system architecture
   across a network.

   Software packages should not create subdirectories
   directly under \filelink{/usr}.  Some symbolic links
   may exist to other locations for compatibility
   purposes.

   This directory is typically read-only data. It
   contains binaries which are not needed in single
   user mode.  It contains the \filelink{/usr/local}
   directory where local binaries and such may be
   stored.  \textbf{man} pages are stored under
   \filelink{/usr/share/man}.

   \begin{important}
      Some recent distributions have abandoned the strategy
      of separating \filelink{/bin}, \filelink{/sbin},
      \filelink{/lib}, and \filelink{/lib64} from their
      partners under \filelink{/usr}, using symbolic links to
      join them.  They view the time-honored concept of
      enabling the possibility of placing \filelink{/usr} on
      a separate partition to be mounted after boot as
      obsolete.
   \end{important}

}


