title: how to delete duplicate lines in a text file in unix bash?
body: <p>I just have a file.txt with multiple lines, I would like to remove duplicate lines without sorting the file. what command can i use in unix bash ? </p>
  
  <p>sample of file.txt</p>
  
  <pre><code>orangejuice;orange;juice_apple
  pineapplejuice;pineapple;juice_pineapple
  orangejuice;orange;juice_apple
  </code></pre>
  
  <p>sample of output:</p>
  
  <pre><code>orangejuice;orange;juice_apple
  pineapplejuice;pineapple;juice_pineapple
  </code></pre>