title: unix join separator char
body: <p>Sorry for the maybe trivial question.</p>
  
  <p>I fought a bit with the unix <em>join</em> command, trying to get tabs instead of whitespaces as the default separators. -t is the argument, but these don't work (ubuntu 9.10 64 bit 2.6.31-14, GNU coreutils version 7.4)</p>
  
  <pre><code>join file1 file2 -t"\t"
  join file1 file2 -t="\t"
  join file1 file2 -t="\\t"
  join file1 file2 -t $"\t"
  </code></pre>
  
  <p>Et cetera. Of course, I can always use some inelegant solution like</p>
  
  <pre><code>join file1 file2 &gt; output
  sed "s/ /\t/g" output
  </code></pre>
  
  <p>But I wanted to look smart :-) Moreover, if there's a -t argument, it must work.</p>