title: awk how to concat number with strings
body: <p>I am trying to append some text after each line of a file. 
  I have a file that each line consist of a number:</p>
  
  <p>123</p>
  
  <p>123</p>
  
  <p>123</p>
  
  <p>if I run <code>awk '{print $1"a"}'</code> myfile.txt I get:</p>
  
  <p>a23</p>
  
  <p>a23</p>
  
  <p>a23</p>
  
  <p>I am pretty sure it is because of the number in the file. I ran it with other files with regular lines this problem doesn't happen. But I couldn't find anywhere talking about this.</p>
  
  <p>I also tried <code>awk'{char=$1"a";print char}'</code></p>