Improve 2019/diels-grabsch1/try.sh

2019/diels-grabsch1/try.sh

@@ -15,34 +15,43 @@ make CC="$CC" all >/dev/null || exit 1
 # clear screen after compilation so that only the entry is shown
 clear
 
-echo "$ dd bs=1024 count=2048 < /dev/zero | compress > ref.Z" 1>&2
+read -r -n 1 -p "Press any key to run: dd bs=1024 count=2048 < /dev/zero | compress > ref.Z: "
+echo 1>&2
 dd bs=1024 count=2048 < /dev/zero | compress > ref.Z
 echo 1>&2
 
-echo "$ dd bs=1024 count=2048 < /dev/zero | ./prog > dg1.Z" 1>&2
+read -r -n 1 -p "Press any key to run: dd bs=1024 count=2048 < /dev/zero | ./prog > dg1.Z: "
+echo 1>&2
 dd bs=1024 count=2048 < /dev/zero | ./prog > dg1.Z
 echo 1>&2
 
-echo "$ cmp ref.Z dg1.Z" 1>&2
+read -r -n 1 -p "Press any key to run: cmp ref.Z dg1.Z: "
+echo 1>&2
 cmp ref.Z dg1.Z
 echo "Exit code of: cmp ref.Z dg1.Z: $?" 1>&2
 echo 1>&2
 
-echo "$ compress < Shakespeare.txt > ref.Z" 1>&2
+read -r -n 1 -p "Press any key to run: compress < Shakespeare.txt > ref.Z: "
+echo 1>&2
 compress < Shakespeare.txt > ref.Z
 echo 1>&2
 
-echo "$ ./prog < Shakespeare.txt > dg1.Z" 1>&2
+read -r -n 1 -p "Press any key to run: ./prog < Shakespeare.txt > dg1.Z: "
+echo 1>&2
 ./prog < Shakespeare.txt > dg1.Z
 echo 1>&2
 
-echo "Notice how the files differ:" 1>&2
-echo "$ cmp ref.Z dg1.Z" 1>&2
+echo "Notice how the two files differ:" 1>&2
+read -r -n 1 -p "Press any key to run: cmp ref.Z dg1.Z: "
+echo 1>&2
 cmp ref.Z dg1.Z # Oops, the files differ
 echo "Exit code of: cmp ref.Z dg1.Z: $?" 1>&2
 echo 1>&2
 
 echo "... and notice how this works fine:" 1>&2
-echo "$ zcat < dg1.Z | cmp - Shakespeare.txt" 1>&2
+read -r -n 1 -p "Press any key to run: zcat < dg1.Z | cmp - Shakespeare.txt: "
+echo 1>&2
 zcat < dg1.Z | cmp - Shakespeare.txt
+echo "Exit code of zcat < dg1.Z | cmp - Shakespeare.txt: ${PIPESTATUS[1]}"
+echo 1>&2
 echo "What happened?"