title: Commands like "uname -s" is not recognized in WSL when executed from poweshell
body: <p>I need to execute the following command in WSL:</p>
  
  <pre><code>sudo curl -L "https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
  </code></pre>
  
  <p>In order to execute it from powershell, i tried to run:</p>
  
  <pre><code>Ubuntu1804 run "sudo curl -L 'https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)' -o /usr/local/bin/docker-compose"
  </code></pre>
  
  <p>But errors occur as it cannot find the value of <code>uname -s</code>  and  <code>uname -m</code></p>
  
  <pre><code>uname : The term 'uname' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling
  of the name, or if a path was included, verify that the path is correct and try again.
  At line:1 char:107
  + ... ocker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(u ...
  +                                                             ~~~~~
      + CategoryInfo          : ObjectNotFound: (uname:String) [], CommandNotFoundException
      + FullyQualifiedErrorId : CommandNotFoundException
  </code></pre>
  
  <p>But the following command works as i manually entered the value of <code>uname -s</code> and  <code>uname -m</code> in that command.</p>
  
  <pre><code> Ubuntu1804 run "sudo curl -L 'https://github.com/docker/compose/releases/download/1.23.2/docker-compose-Linux-x86_64' -o /usr/local/bin/docker-compose"
  </code></pre>
  
  <p>Can anyone please help me to find when using powershell, how to incorporate the results of some commands to another command and execute it in WSL?</p>
  
  <p>Also, how can i incorporate the value of environment variables like <code>$USER</code> in WSL commands and execute from powershell?</p>