basics: sh-programming: more variable setting examples

There are several methods of setting and printing variables. Add a
couple frames to help clarify that before jumping into the more
complex examples.

Signed-off-by: John Ogness <john.ogness@linutronix.de>

1 files changed, 31 insertions, 0 deletions

diff --git a/linux-basics/sh-programming/pres_sh-programming_de.tex b/linux-basics/sh-programming/pres_sh-programming_de.tex
index 37fbafb..2af143f 100644
--- a/linux-basics/sh-programming/pres_sh-programming_de.tex
+++ b/linux-basics/sh-programming/pres_sh-programming_de.tex
@@ -25,6 +25,37 @@ echo Hello World
 \end{frame}
 
 \begin{frame}[fragile]
+\frametitle{Variablen}
+\begin{lstlisting}
+#!/bin/sh
+
+# VAR1 defined for this process
+VAR1=abc
+
+# now VAR1 is defined for children processes
+export VAR1
+
+# VAR2 defined only for /bin/sh child process
+# (with export set)
+VAR2=def /bin/sh
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Variablen}
+\begin{lstlisting}
+#!/bin/sh
+
+VAR1=abc
+
+echo $VAR1
+
+echo ${VAR1}
+
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
 \frametitle{Variablen und Parameter}
 \begin{lstlisting}
 #!/bin/sh