title: Grep -f only returns full input file
body: <p>I need to isolate specific genes from the CARD database (basically fasta files). I created a list of gene names of interest to use</p>
  
  <pre><code>grep -wA1 -f list.file database.file
  </code></pre>
  
  <p>(A1 to get the respective sequence as well)</p>
  
  <p>The problem is, that even though the command is correctly identifying the genes of interest, the output is still the complete database.file just with the search patterns marked. That is of course not helping too much...</p>
  
  <p>Does someone know what I do wrong? I know, that the problem is solvable by loops, but I think the -f option would be exactly what I need, plus it used to work nicely.</p>