title: One line if/else condition in linux shell scripting
body: <p>I would like to have the equivelant of the following in a one line if/else condition.</p>
  
  <pre><code>$maxline=`cat journald.conf | grep "#SystemMaxUse="`
  if [ $maxline == "#SystemMaxUse=" ]
  then
      sed 's/\#SystemMaxUse=/SystemMaxUse=50M/g' journald.conf &gt; journald.conf2
      mv journald.conf2 journald.conf;
  else
      echo "This file has been edited. You'll need to do it manually."
  fi  
  </code></pre>
  
  <p>I'm attempting to put this into a one line command. So far I've gotten it all but the else portion of the command. Here's what I have so far...</p>
  
  <pre><code>maxline=`cat journald.conf | grep "#SystemMaxUse="` &amp;&amp; if [ $maxline == "#SystemMaxUse=" ]; then sed 's/\#SystemMaxUse=/SystemMaxUse=50M/g' journald.conf &gt; journald.conf2 &amp;&amp; mv journald.conf2 journald.conf; fi
  </code></pre>
  
  <p>So how can I include the else portion of the above code into my command? Thank you for your help in advance.</p>