title: How to find words which contain the first 3 characters input by a user
body: <p>How can I find words which contain the first 3 characters input by a user. If the file contains words NYL000234 and other words, and user gives an input like NYL, then output would be NYL000234.</p>
  
  <p>Example - Text file contains -</p>
  
  <pre><code>10099834 COL01139 OD 1_1_2_1
  T1 10115177 COL01356 OD 1_1_3_1
  T1 10099848 COL03031 OD 1_1_2_1
  T1 10093544 COL03008 OD 1_1_1_1
  T1 10101126 COL03050 ID
  1_1_2_1 10093697 COL03002 ID
  1_1_3_1 10122993 COL05067 ID
  1_1_2_1 10093668 COL03047 ID
  1_1_2_1 10127012 COL05077 ID
  1_1_3_1 10093664 COL03045 ID 1_1_2_1 
  </code></pre>
  
  <p>If the user gives input COL then output would be like this..
  (output should be column not in row) </p>
  
  <pre><code>COL01139
  COL01356
  COL03031
  COL03008
  COL03050
  COL03002
  COL05067
  COL03047
  COL05077
  COL03045 
  </code></pre>