\frametitle{PATH: Finding Programs}
\begin{block}{How does the shell know where 'ls' is?}
The \texttt{PATH} environment variable is a list of directories the shell searches through every time you type a command.
\end{block}
\begin{exampleblock}{Key Points}\label{sec:orga95829a}
\begin{itemize}
\item Colon-separated list: \texttt{/usr/local/bin:/usr/bin:/bin}
\item \alert{First match wins:} The shell searches from left to right.
\item If it's not in \texttt{PATH}, use an explicit path (e.g., \texttt{/usr/local/bin/my\_prog} or \texttt{./my\_prog}).
\end{itemize}
\end{exampleblock}
