title: tr command in awk to change the column values
body: <p>I am using in my shell script TR command in awk to mask the data.  Below example file  affects only first line of the my file when i used tr command in awk. when i use the same in <strong>while</strong> loop and called the awk command inside of it then its working fine but it taking very long time to get completed. Now my requirement i want to mask many columns[example :$1, $5, $9] in the same file(file.txt) and this should affect the whole file not first line and i want to achieve this as much as faster to mask the data.  Please advise</p>
  
  <p>cat file.txt<br>
   ========<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek,lskjsjshsh<br>
  abcbchs,degehek<br>
  abcbchs,degehek,lskjsjshsh   </p>
  
  <h1>OUTPUT</h1>
  
  <pre><code>awk -F"," -v OFS=","  '{ "echo \""$1"\" | tr \"a-c\" \"e-f\" | tr \"0-5\" \"6-9\"" | getline $1 }7' file.txt
  </code></pre>
  
  <p>effffhs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek<br>
  abcbchs,degehek,lskjsjshsh<br>
  abcbchs,degehek<br>
  abcbchs,degehek,lskjsjshsh    </p>
  
  <h1>Expected output</h1>
  
  <p>effffhs,degehek<br>
  effffhs,degehek<br>
  effffhs,degehek<br>
  effffhs,degehek<br>
  effffhs,degehek<br>
  effffhs,degehek,lskjsjshsh<br>
  effffhs,degehek<br>
  effffhs,degehek,lskjsjshsh  </p>