title: How to ADB "reboot download" in bash script?
body: <p>I would like to reboot many Android devices to download mode simultaneously.</p>
  
  <p>Both of the following work from the command line:</p>
  
  <pre><code>    adb reboot
      adb reboot download
  </code></pre>
  
  <p>The following bash script also works:</p>
  
  <pre><code>adb devices | while read line
  do
      if [ ! "$line" = "" ] &amp;&amp; [ `echo $line | awk '{print $2}'` = "device" ]
      then
          device=`echo $line | awk '{print $1}'`
          echo "$device $@ ..."
          adb -s $device "reboot" &amp;
      fi
  done
  </code></pre>
  
  <p>However, when I replace 'reboot' with 'reboot download', the script only provides ADB usage instructions: </p>
  
  <pre><code>user@user /home 
  $ ./rebootToDownload.bsh 
  29f7654c  ...
  
  user@user /home 
  $ Android Debug Bridge version 1.0.31
  
   -a                            - directs adb to listen on all interfaces for a connection
   -d                            - directs command to the only connected USB device
                                   returns an error if more than one USB device is present.
   -e                            - directs command to the only running emulator.
   ...
  </code></pre>
  
  <p>Could someone please explain why 'ADB reboot' executes successfully, but not 'ADB reboot download'?</p>
  
  <p>Is there any way around this?</p>
  
  <p>Any help is appreciated.</p>