added insecured code to example

mod.ts

@@ -1,100 +1,14 @@
 import { Command } from "https://deno.land/x/cliffy@v0.25.7/command/mod.ts";
-import { DB } from "https://deno.land/x/sqlite/mod.ts";
-import {join} from "https://deno.land/std@0.178.0/path/mod.ts";
-
-// for the demo, we will place the state in the /tmp instead of $HOME
-const HOME_DIRECTORY = '/tmp';
-const CLI_STATE_DIRECTORY = join(HOME_DIRECTORY, 'deno-cli-example');
-
-// the CLI will need read and write access to /tmp/deno-cli-example directory
-await Deno.mkdir(CLI_STATE_DIRECTORY, {recursive: true});
-const MAIN_DB_FILE = join(CLI_STATE_DIRECTORY, 'state.sqlite');
 
 
-/**
- * Create tables in the database.  This function is a
- * trivial data migration algorithm.
- */
-function initDB(){
-  const db = new DB(MAIN_DB_FILE);
-  const init_db = `
-  CREATE TABLE IF NOT EXISTS usernames (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      username TEXT,
-      creation_ts DATETIME DEFAULT CURRENT_TIMESTAMP
-  )
-  `;
-  try {
-    db.execute(init_db);
-  } finally {
-    db.close();
-  }
+async function helloWorld(options, ...args) {
+  await Deno.writeTextFile("/dev/null", "hello world.", {append: true});
+  console.log('"hello world" has been written into /dev/null');
 }
 
-/**
- * Returns the latest username saved in the state.
- */
-function getUsernameFromDB(){
-  const db = new DB(MAIN_DB_FILE);
-  try {
-    return db.query(`SELECT username 
-                     FROM usernames 
-                     ORDER BY creation_ts 
-                     DESC LIMIT 1`)[0]
-  } finally {
-    db.close();
-  }
-}
-
-/**
- * Set the passed username in the database.
- */
-function setUsernameInDB(username: string){
-  const db = new DB(MAIN_DB_FILE);
-  try {
-    return db.query("INSERT INTO usernames (username) VALUES (?)", [username])
-  } finally {
-    db.close();
-  }
-}
-
-function getUsernameOrDefault(name?: string): string{
-  return name || getUsernameFromDB() || 'no username set yet.';
-}
-
-/**
- * Calls httpbin.org/get with the username as argument.
- */
-async function getFromService(options){
-  const username = getUsernameOrDefault(options.usermame);
-  const encodedUsername = encodeURIComponent(username);
-  const url = `https://httpbin.org/get?username=${encodedUsername}`;
-  const response = await fetch();
-  console.log(await response.json());
-}
-
-async function setProperties(options){
-  if(options.username){
-    setUsernameInDB(options.username);
-  }
-}
-
-initDB();
 await new Command()
   .name("deno-cli-example")
   .version("0.1.0")
   .description("Example of a deno CLI.")
-  .command('call-service')
-  .description('Example of a real use case. call-service will called '
-                + 'https://httpbin.org/get with username passed as parameter.')
-  .option("--username <username>", 
-          'username to use in the service call. If no username specified, the '
-           + ' persisted username  will be used.')
-  .action(getFromService)
-  .command('set-properties')
-  .description('Persist properties to state. Persisted properties will then '
-                + 'be used as default in other commands')
-  .option("--username <username>", "Set the default username property.", 
-          {required: true})
-  .action(setProperties)
+  .action(helloWorld)
   .parse(Deno.args);