title: awk: add new column, including header
body: <p>I have a file that looks like this:</p>
  
  <pre><code>name measurement gender duration
  a 1 m 55
  b 1 f 54
  c 2 m 53
  ... etc
  </code></pre>
  
  <p>I want to use awk to add a column, which has the same value for every row, except the first (the header). Let's say I want to add the column new_column with the value 99 for every row, so the output file looks like this:</p>
  
  <pre><code>name measurement gender duration new_column
  a 1 m 55 99
  b 1 f 54 99
  c 2 m 53 99
  ... etc
  </code></pre>
  
  <p>This sounds like a job for awk... but I haven't been able to figure out how. Any ideas? Many thanks!</p>