Improve 1996/gandalf/try.sh

1996/gandalf/try.sh

@@ -23,98 +23,83 @@ rm -f hatcat.txt cathat.txt hatcat2.txt cathat2.txt hatcat3.txt cathat3.txt
 
 trap 'rm -f hatcat.txt cathat.txt hatcat2.txt cathat2.txt hatcat3.txt cathat3.txt; exit' 0 1 2 3 15
 
-delete_tmp_files()
-{
-    rm -f hatcat.txt cathat.txt hatcat2.txt cathat2.txt hatcat3.txt cathat3.txt
-    return 0
-}
-press_any_key()
-{
-    echo 1>&2
-    read -r -n 1 -p "Press any key to continue (q = quit): " 1>&2
-    test "$REPLY" = "q" && delete_tmp_files && echo 1>&2 && exit
-}
-
 show_diff()
 {
     if [[ "$#" -ne 2 ]]; then
 	echo "$0: show_diff expects two args, got: $#" 1>&2
 	exit 1
     fi
-    echo "$ diff $1 $2" 1>&2
+    read -r -n 1 -p "Press any key to run: diff $1 $2: "
+    echo 1>&2
     diff "$1" "$2" && echo "$1 and $2 are identical"
+    echo 1>&2
 }
 
-echo "Notice how the programs are the same:" 1>&2
+read -r -n 1 -p "Press any key to run: diff -s hatcat cathat: "
+echo 1>&2
 diff -s hatcat cathat
-press_any_key
+echo 1>&2
 
-echo "Now notice how running both cathat and hatcat in different ways" 1>&2
+echo "Next notice how running both cathat and hatcat in different ways" 1>&2
 echo "shows different output." 1>&2
-press_any_key
 
-echo "Running hatcat without a path:" 1>&2
-echo "$ PATH=.:\$PATH" 1>&2
+read -r -n 1 -p "Press any key to run: PATH=.:\$PATH: "
+echo 1>&2
 PATH=.:$PATH
-echo "$ hatcat | tee hatcat.txt" 1>&2
+read -r -n 1 -p "Press any key to run: hatcat | tee hatcat.txt (no path): "
+echo 1>&2
 hatcat | tee hatcat.txt
-press_any_key
+echo 1>&2
 
-echo "Running cathat without a path:" 1>&2
-echo "$ cathat | tee cathat.txt" 1>&2
+read -r -n 1 -p "Press any key to run: cathat | tee cathat.txt (no path): "
+echo 1>&2
 cathat | tee cathat.txt
-press_any_key
+echo 1>&2
 
 echo "Showing diff between the above two commands, 'hatcat' and './cathat':" 1>&2
 show_diff hatcat.txt cathat.txt
-press_any_key
 
-echo "Now watch ./hatcat:" 1>&2
+read -r -n 1 -p "Press any key to run: ./hatcat | tee hatcat2.txt: "
+echo 1>&2
 ./hatcat | tee hatcat2.txt
-press_any_key
 
-echo "Now watch ./cathat:" 1>&2
+read -r -n 1 -p "Press any key to run: ./cathat | tee cathat2.txt: "
+echo 1>&2
 ./cathat | tee cathat2.txt
-press_any_key
 
 echo "Showing diff between running 'hatcat' and './hatcat':" 1>&2
 show_diff hatcat.txt hatcat2.txt
-press_any_key
 
-echo "Now watch \$(pwd)/cathat" 1>&2
+read -r -n 1 -p "Press any key to run: \$(pwd)/cathat | tee cathat3.txt: "
+echo 1>&2
 "$(pwd)"/cathat | tee cathat3.txt
-press_any_key
 
-echo "Finally, watch \$(pwd)/hatcat" 1>&2
+read -r -n 1 -p "Press any key to run: \$(pwd)/hatcat | tee hatcat3.txt: "
+echo 1>&2
 "$(pwd)"/hatcat | tee hatcat3.txt
-press_any_key
 
 echo "Showing diff between running './hatcat' and './cathat':" 1>&2
 show_diff hatcat2.txt cathat2.txt
-press_any_key
 
 echo "Showing diff between running '\$(pwd)/hatcat' and '\$(pwd)/cathat':" 1>&2
 show_diff hatcat3.txt cathat3.txt
-press_any_key
 
 echo "Showing diff between running '\$(pwd)/hatcat' and 'hatcat':" 1>&2
 show_diff hatcat3.txt hatcat.txt
-press_any_key
 
 echo "Showing diff between running '\$(pwd)/hatcat' and './hatcat':" 1>&2
 show_diff hatcat3.txt hatcat2.txt
-press_any_key
 
 echo "Showing diff between running '\$(pwd)/cathat' and 'cathat':" 1>&2
 show_diff cathat3.txt cathat.txt
-press_any_key
 
 echo "Showing diff between running '\$(pwd)/cathat' and './cathat':" 1>&2
 show_diff cathat3.txt cathat2.txt
-press_any_key
 
 # remove temporary files
 rm -f hatcat.txt cathat.txt hatcat2.txt cathat2.txt hatcat3.txt cathat3.txt
 
 echo 1>&2
 echo "Now answer: why did some of the same programs execute differently?" 1>&2
+
+rm -f hatcat.txt cathat.txt hatcat2.txt cathat2.txt hatcat3.txt cathat3.txt