title: Discord bot replies multiple times
body: <p>im trying to make my first discord bot that executes a command but the problem is that if a user dms !command to the bot with a link, the bot replies multiple times because the command executes multiple times.</p>
  
  <pre><code>client.on('message', msg1 =&gt; {
    if (msg1.content.startsWith("!command")) {
      var splitMessage = msg1.content.split(" ");
      if (splitMessage[1] != undefined) {
        var url = splitMessage[1];
        if (url.includes("google.com")) {
          var execSync = require('child_process').execSync;
          var x = Math.floor((Math.random() * 9999999999) + 1);
          var cmd = 'wkhtmltopdf ' + url + ' ' + x + '.pdf';
  
          var options = {
            encoding: 'utf8'
          }
  
          var filename = x + '.pdf';
          console.log(execSync(cmd, options));
          msg1.reply({ files: [filename] });
        }
      }
    }
  });
  </code></pre>