title: grep with wildcard symbols
body: <p>Wildcard search with grep</p>
  
  <p>I have a file that contains many IP addresses. I wanted to list all the ip addresses in the file and I used grep with a pattern 192.16* but it doesn't show the whole list of IP addresses. I am able to list the whole IP addresses only while using period followed with an asterisk symbol. So my doubt is Why 2nd option not working but 3rd option works fine.</p>
  
  <pre><code>root@test:~/test# cat z
  192.168.1.0
  192.168.2.0
  192.168.110.7
  192.168.115.5
  
  1. root@test:~/test# grep -o 192.1 z
  192.1
  192.1
  192.1
  192.1
  
  
  2. root@test:~/test# grep -o 192.1* z
  192.1
  192.1
  192.1
  192.1
  
  3. root@test:~/test# grep -o 192.1. z
  192.16
  192.16
  192.16
  192.16
  
  
  4. root@test:~/test# grep -o 192.1.* z
  192.168.1.0
  192.168.2.0
  192.168.110.7
  192.168.115.5
  </code></pre>