title: How to delete lines from file with sed\awk?
body: <p>I have file, with lines, contains ip with netmask
  a.b.c.d/24
  w.x.y.z/32
  etc
  How to delete delete specific row? 
  i'm using  </p>
  
  <pre><code>sed -ie "s#a.b.c.d/24##g" %filname%
  </code></pre>
  
  <p>but after the removal is an empty string in file. </p>
  
  <p>It should run inside a script, with ip as parameter and also work in freebsd under sh. </p>