title: Concatenate variable in string bash
body: <p>Im killing the process in the port 4444, but this can change, i have the port in a variable PORT, but i cant find how to put this in the instruction </p>
  
  <pre><code>netstat -ntlp | awk '$4~/:*4444$/{gsub(/\/.*/,"",$NF);cmd="kill -9 "$NF;system(cmd)}'
  </code></pre>
  
  <p>I have tried with:</p>
  
  <pre><code>netstat -ntlp | awk '$4~/:*${PORT}$/{gsub(/\/.*/,"",$NF);cmd="kill -9 "$NF;system(cmd)}'
  </code></pre>
  
  <p>But it doesnt work</p>