Improve scripts of 2013/dlowe

The try.sh script cannot be modified to prompt the user to run commands
as the other scripts (or at least one, diff.sh) make use of tail(1) on
the output. The script diff.sh however can have that and it has been
done.

Minor fixes in display in slflen.sh.

2013/dlowe/diff.sh

@@ -11,12 +11,20 @@ if [[ -z "$CC" ]]; then
 fi
 make CC="$CC" all >/dev/null || exit 1
 
-echo "$ ./try.sh | tail -n 3 > 1.txt" 1>&2
-./try.sh | tail -n 3 > 1.txt
+read -r -n 1 -p "Press any key to run: ./try.sh | tail -n 3 | tee 1.txt: "
+./try.sh | tail -n 3 | tee 1.txt
+
 echo "$ echo 'IOCCC winning entry 2013/dlowe' > ioccc.txt" 1>&2
-echo 'IOCCC winning entry 2013/dlowe' > ioccc.txt
-echo "$ ./try.sh | tail -n 3 > 2.txt" 1>&2
-./try.sh | tail -n 3 > 2.txt
-echo "$ diff 1.txt 2.txt" 1>&2
-diff 1.txt 2.txt
+read -r -n 1 -p "Press any key to run: echo 'IOCCC winning entry 2013/dlowe' | tee ioccc.txt: "
+echo 1>&2
+echo 'IOCCC winning entry 2013/dlowe' | tee ioccc.txt
+
+read -r -n 1 -p "Press any key to run: ./try.sh | tail -n 3 | tee 2.txt: "
+echo 1>&2
+./try.sh | tail -n 3 | tee 2.txt
+echo 1>&2
+
+read -r -n 1 -p "Press any key to run: diff -s 1.txt 2.txt: "
+echo 1>&2
+diff -s 1.txt 2.txt
 rm -f 1.txt 2.txt ioccc.txt

2013/dlowe/slflen.sh

@@ -15,5 +15,7 @@ make CC="$CC" all >/dev/null || exit 1
 
 ln -sf dlowe sparkl
 ls -1 *
+echo 1>&2
 echo -n "sparkline length of above files: "
 wc -c ./* | awk '{print $1}' | xargs ./sparkl
+echo 1>&2