title: Egrep acts strange with -f option
body: <p>I've got a strangely acting <code>egrep -f</code>.</p>
  
  <p>Example:</p>
  
  <pre><code>$ egrep -f ~/tmp/tmpgrep2 orig_20_L_A_20090228.txt | wc -l
  3
  $ for lines in `cat ~/tmp/tmpgrep2` ; do  egrep $lines orig_20_L_A_20090228.txt ; done | wc -l
  12
  </code></pre>
  
  <p>Could someone give me a hint what could be the problem?
  No, the files did not changed between executions. The expected answer for the egrep line count is 12.</p>
  
  <p>UPDATE on file contents: the searched file contains cca 13000 lines, each of them are 500 char long, the pattern file contains 12 lines, each of them are 24 char long. The pattern always (and only) occurs on a fixed position in the seached file (26-49).</p>
  
  <p>UPDATE on pattern contents: every pattern from tmpgrep2 are a 24 char long number.</p>