title: right syntax using command sh in jenkinsfile
body: <p>I´m trying to remove image with same ids using a jenkinksfile, I´ve tried:</p>
  
  <pre><code>sh "docker images | grep 643975c526cf | awk '{print `$1` ':' `$2`}' | xargs docker rmi"
  
  sh "docker images | grep 643975c526cf | awk '{print \$1 ':' \$2}' | xargs docker rmi"
  
  sh "docker images | grep 643975c526cf | awk '{print ${1} ':' ${2}}' | xargs docker rmi"
  </code></pre>
  
  <p>but the syntax is wrong on awk '{print ${1} ':' ${2}}' in the linux using the command line work fine but I don´t know the right syntex on sh command.</p>