Initial data commit

Task/Stack/UnixPipes/stack-1.up

@@ -0,0 +1,11 @@
+init() { if [ -e stack ]; then rm stack; fi } # force pop to blow up if empty
+push() { echo $1 >> stack; }
+pop() {
+	tail -1 stack;
+	x=`head -n -1 stack | wc -c`
+	if [ $x -eq '0' ]; then rm stack; else
+		truncate -s `head -n -1 stack | wc -c` stack
+	fi
+}
+empty() { head -n -1 stack |wc -l; }
+stack_top() { tail -1 stack; }