title: Grep recursively - how to only show files containing the string, and not files of subdir
body: <p>I want to use grep to search for files.</p>
  
  <p>In this particular case I want to search my home directory - /home/unknwn - for files containing the string 'i3'.</p>
  
  <p>Whilst searching the net for how to do this, I got the impression that the -H flag would do this for me. It didn't, though. Well, it DOES find directories with the string 'i3', but it also lists all the files in that directory, most of which are not contaning the string at all.</p>
  
  <p>I will post some terminal output to show what I mean (I shortened it down a bit and added line numbers):</p>
  
  <pre><code>  1  » grep -rH 'i3' /home/unkownentity
    2 /home/unkownentity/Dropbox/databas.key:         &lt;Data&gt;i33L/amU9Hye95PjMSHAbTruRI/aOX0L4e8pY/0/mh0=&lt;/Data&gt;
    3 Binary file /home/unkownentity/Dropbox/maszeW-2015/Screenshot_2015-02-14-09-40-19.png matches
    4 Binary file /home/unkownentity/Dropbox/maszeW-2015/maszeW-2015.png matches
    5 Binary file /home/unkownentity/Dropbox/maszeW-2015/Templates/ett.zw matches
    6 Binary file /home/unkownentity/Dropbox/IMG_20131130_095638.jpg matches
    7 Binary file /home/unkownentity/Dropbox/fonts/ailerons.zip matches
    8 Binary file /home/unkownentity/Dropbox/poker-odds-chart.pdf matches
    9 Binary file /home/unkownentity/Dropbox/Widgets/uccw/uccw-req/request/htc weather/slight drizzle.png matches
   10 Binary file /home/unkownentity/Dropbox/Widgets/uccw/uccw-req/request/htc weather/mostly cloudy.png matches
   11 Binary file /home/unkownentity/Dropbox/Widgets/uccw/uccw-req/request/htc weather/chance of rain.png matches
   12 Binary file /home/unkownentity/Dropbox/Widgets/uccw/uccw-req/request/htc weather/chance of snow.png matches
   13 Binary file /home/unkownentity/Dropbox/Widgets/uccw/uccw-req/request/htc weather/hail.png matches
   14 Binary file /home/unkownentity/Dropbox/Widgets/uccw/uccw-req/request/htc weather/freezing drizzle.png matches
  </code></pre>
  
  <p>Okay. What's happened here is that instead of showing all files containing 'i3' is actually:
  Line 2 contains the word 'i3'. So far, so good. But then, it goes on to list all files in all subdirectories of the file that contained 'i3', none of which contain the string.</p>
  
  <p>What's happened here, and what am I doing wrong? I want to use only grep, without any other commands. Would appreciate some help.</p>