Update simple example.

examples/simple/.gitignore

@@ -0,0 +1 @@
+history

examples/simple/20-shell.sh

@@ -1,5 +1,5 @@
 #!/bin/bash -
 source functions
-add_history guestfish -a vm1.img
-add_history guestfish -a vm2.img -m /dev/sda1
-terminal --title="Guestfish demonstration"
+add_history echo History command number 2
+add_history echo '"History command number 1"'
+terminal --title="Press the UP ARROW to get history"

examples/simple/30-goodbye.html

@@ -6,11 +6,21 @@
 </p>
 
 <p>
-Now look at these files to find out how we did it:
+We hope you noticed on the previous slide that you
+could hit the <b>Up arrow</b> to get pre-populated
+history.
+</p>
+
+<p>
+Now look at these files in the current directory
+to find out how we did it:
 </p>
 
 <ul>
 <li> 10-hello.html
 <li> 20-shell.sh
 <li> 30-goodbye.html
+<li> functions &mdash; common shell functions
+<li> style.css &mdash; stylesheet
+<li> code.js &mdash; Javascript
 </ul>

examples/simple/functions

@@ -1,14 +1,14 @@
 # -*- shell-script -*-
 
-# Need a short sleep to allow the previous shell to exit, possibly
-# writing to the history file, before we start the new shell.  Could
-# write to a different history file each time which would avoid this.
-sleep 1
+# Place any local environment variables required in 'local'.
+if [ -f local ]; then source local; fi
 
 export PS1="$ "
-export HISTFILE=/tmp/history
+
+export HISTFILE=$talkdir/history
 
 rm -f $HISTFILE
+touch $HISTFILE
 
 add_history ()
 {
@@ -17,6 +17,11 @@ add_history ()
 
 terminal ()
 {
+    # Make $HISTFILE unwritable so the shell won't update it
+    # when it exits.
+    chmod -w $HISTFILE
+
+    # Run gnome-terminal.
     exec \
         gnome-terminal \
         --window \