Data commit

Task/Menu/UNIX-Shell/menu.sh

@@ -0,0 +1,19 @@
+# choose 'choice 1' 'choice 2' ...
+#   Prints menu to standard error. Prompts with PS3.
+#   Reads REPLY from standard input. Sets CHOICE.
+choose() {
+    CHOICE=                     # Default CHOICE is empty string.
+    [[ $# -gt 0 ]] || return    # Return if "$@" is empty.
+    select CHOICE; do           # Select from "$@".
+        if [[ -n $CHOICE ]]; then
+            break
+        else
+            echo Invalid choice.
+        fi
+    done
+}
+
+PS3='Which is from the three pigs: '
+choose 'fee fie' 'huff and puff' 'mirror mirror' 'tick tock'
+[[ -n $CHOICE ]] && echo You chose: $CHOICE
+[[ -z $CHOICE ]] && echo No input.