title: Grepping exact value but printing entire line
body: <p>I have a 2-column tab-separated file that I need to grep specific information from.
  The file looks like this:</p>
  
  <pre><code>wych_hazel    agt|plt
  wytensin    agt
  x    agt|com|qud
  xanax    agt
  xtc    agt
  xylocaine    agt
  yellow_jacket    agt|anm
  </code></pre>
  
  <p>I need to grep from the 2nd column, those lines that ONLY have the value <code>agt</code>.</p>
  
  <p>The desired output would be this:</p>
  
  <pre><code>wytensin    agt
  xanax    agt
  xtc    agt
  xylocaine    agt
  </code></pre>
  
  <p>I have tried:</p>
  
  <pre><code>grep -e 'agt' input
  </code></pre>
  
  <p>which gives me:</p>
  
  <pre><code>wych_hazel    agt|plt
  wytensin    agt
  x    agt|com|qud
  xanax    agt
  xtc    agt
  xylocaine    agt
  yellow_jacket    agt|anm
  </code></pre>
  
  <p>then I have tried:</p>
  
  <pre><code>grep -oh 'agt' input
  </code></pre>
  
  <p>which gives me:</p>
  
  <pre><code>agt
  agt
  agt
  agt
  agt
  agt
  agt
  </code></pre>
  
  <p>What <code>grep</code> parameters should I introduce to arrive at my desired result?</p>