Improve and fix 2011/fredriksson/try.sh

The script now writes the output to a file (via tee(1)) and uses diff -s
on the file and fredriksson.c. It also fixes a problem where if one were
to hit space after the prompt (lines would be merged) rather than
enter/return.

Fixed shellcheck warning (no need to ignore it).

2011/fredriksson/.gitignore

@@ -5,6 +5,7 @@ ag.c
 *.dSYM
 fredriksson
 fredriksson.orig
+fredriksson.txt
 indent
 indent.c
 indent.o

2011/fredriksson/try.sh

@@ -15,17 +15,25 @@ make CC="$CC" all >/dev/null || exit 1
 # clear screen after compilation so that only the entry is shown
 clear
 
+# remove temporary file
+rm -f fredriksson.txt
 
-echo "$ ./fredriksson -k3 cat < fredriksson.c" 1>&2
-read -r -n 1 -p "Press any key to have the program show its source code: "
+echo "$ ./fredriksson -k3 cat < fredriksson.c | tee fredriksson.txt" 1>&2
+read -r -n 1 -p "Press any key to have the program show its own code (space = next page, q = quit): "
+echo 1>&2
+./fredriksson -k3 cat < fredriksson.c | tee fredriksson.txt | less -rEXF
 echo 1>&2
-./fredriksson -k3 cat < fredriksson.c
 
-read -r -n 1 -p "Press any key to continue: "
+read -r -n 1 -p "Press any key to run: diff -s fredriksson.c fredriksson.txt: "
 echo 1>&2
-read -r -n 1 -p "Press any key to run: ./fredriksson -k1 -i POOT < /etc/group: "
+diff -s fredriksson.c fredriksson.txt
 echo 1>&2
-./fredriksson -k1 -i POOT < /etc/group
+rm -f fredriksson.txt
+
+echo "$ ./fredriksson -k1 -i POOT < /etc/group" 1>&2
+read -r -n 1 -p "Press any key to continue (space = next page, q = quit): "
+echo 1>&2
+./fredriksson -k1 -i POOT < /etc/group | less -rEXF
 echo 1>&2
 
 read -r -n 1 -p "Press any key to run: ./fredriksson -ck0 [0-9] < fredriksson.c: "
@@ -36,12 +44,15 @@ echo 1>&2
 read -r -n 1 -p "Press any key to run: ./fredriksson -ck0 [0-9] < ag.c: "
 echo 1>&2
 ./fredriksson -ck0 [0-9] < ag.c
+echo 1>&2
 
-echo "Trying to set unlimited stack space for this process..." 1>&2
-ulimit -s unlimited 2>/dev/null
-if [[ "$?" -ne 0 ]]; then
-    echo "...couldn't set unlimited stack space, will skip command." 1>&2
+if ! ulimit -s unlimited 2>/dev/null; then
+    echo "Couldn't set unlimited stack space, skipping next command." 1>&2
 else
-    read -r -n 1 -p "Press any key to run: ./fredriksson -k2 -t -n bofuskate < /usr/share/dict/words: "
+    echo "Set unlimited stack space, continuing." 1>&2
+    echo 1>&2
+    echo "$ ./fredriksson -k2 -t -n bofuskate < /usr/share/dict/words" 1>&2
+    read -r -n 1 -p "Press any key to continue (space = next page, q = quit): "
+    echo 1>&2
     ./fredriksson -k2 -t -n bofuskate < /usr/share/dict/words
 fi