title: Awk print lines starting with regex (IP address)
body: <p>Im trying to read a file for those lines which has IP address on the first column.</p>
  
  <p>my command below does not return any value.</p>
  
  <pre><code>cat test.csv | awk '$1 == "^[[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}]" { print $0 }'
  </code></pre>
  
  <p>The regex can capture IP address.</p>
  
  <p>Tried the below too,</p>
  
  <pre><code>cat test_1.csv | awk '$1~/^[[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\]/ {print $0}'
  </code></pre>
  
  <p><strong>test.csv</strong></p>
  
  <pre><code>1.1.1.1 ipaddress gateway
  2.2.2.2 ipaddress_2 firewall
  www.google.com domain google
  </code></pre>