title: Using each line of awk output as grep pattern
body: <p>I want to find every line of a file that contains any of the strings held in a column of a different file.</p>
  
  <p>I have tried<br>
  <code>grep "$(awk '{ print $1 }' file1.txt)" file2.txt</code><br>
  but that just outputs file2.txt in its entirety.</p>
  
  <p>I know I've done this before with a pattern I found on this site, but I can't find that question anymore.</p>