title: looping "for..do" on bash shell
body: <p>How to do a <code>for do</code> loop in bash shell for executing some application?</p>
  
  <p>I have this code below, i want to run usb-servo app, given the value of usb-servo from 190 to 225, i have tried to run the code, but the <code>for do</code> didn't gave any output, my servo didn't move.</p>
  
  <pre><code>#! /bin/sh
  i=190
  
  sleep 0.4
  for (( i=190;i&lt;=225;i++ ))
  do
  echo my_pass | sudo -S /usr/bin/usb-servo set 0 $i
  done
  
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 195
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 200
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 205
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 210
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 215
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 220
  #echo my_pass | sudo -S /usr/bin/usb-servo set 0 225
  </code></pre>