\frametitle{Command Substitution Examples}
\begin{block}{Substitution Syntax}
\begin{verbatim}
# Using $(command) syntax (preferred)
echo "Today is $(date)"
files=$(ls -1)
echo "Found $(wc -l < file.txt) lines"

# Using backticks (older syntax)
echo "Today is `date`"

# Nested substitution
echo "User $(whoami) in $(pwd)"
\end{verbatim}
\end{block}
