ExecCommand (activity)

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ExecCommand
Status:	beta
Version:	1
Base:	No
Source:	unknown
l10n:	missing
Contributors
JT Olds

This activity does not work with Update.1, due to the improved security policies Update.1 contains. This activity tries to launch other Linux processes, which seems to be disliked by the activity-sandboxing system. If anyone has any ideas on how to fix this, let me know. -JT

Summary

This utility is targeted at experienced Linux/Unix users who hope to feel more at home with the XO. On launch, this activity either launches a predefined Unix command (you have to edit the script contained in the activity), or starts an graphical dialog and queries the user for what command to run. Useful for starting vncviewer or xmms.

Packages

You can find the current version at http://jtolds.googlepages.com/ExecCommand.xo. This version starts a simple xdialog that requests for a command to run. Also, there is a modified version that just starts XMMS. http://jtolds.googlepages.com/Xmms.xo

Justification for implementation

Looking through the Sugarizing page, it seems fairly clear that getting an Activity to simply start a non-activity application cleanly is non-trivial. Many attempts end up leaving a "loading" icon for the activity, or have multiple icons displayed as running activities, or other things.

Native X applications on the XO simply show as a little circle icon, but a lot of work has gone into customizing this behavior for specific X applications.

Personally, I couldn't care less what the icon looks like in the running activities disc, just so long as I can easily start my desired app.

I realized a simple solution would be to create an Activity that simply starts, forks a new app in the process, and then closes itself, cleaning up all of the Activity mess left behind from a rapid exit.

Bugs

The previous justification might be pretty poor considering it still doesn't work sometimes. It seems it works the least when the processor is under a heavier load. It makes me think that my method is working due to some side effect that isn't being noticed by Sugar when the processor has too much to do.

Implementation

import os
# get the exec script started right away.
os.system("bin/exec-script.sh &")

from sugar.activity import activity

class ExecActivity(activity.Activity):

   def __init__(self, handle):
       activity.Activity.__init__(self, handle)

       self.set_title('Executing...')

       # this strategy doesn't seem to work if there's no toolbox
       toolbox = activity.ActivityToolbox(self)
       self.set_toolbox(toolbox)
       toolbox.show()

       # close, removing the unuseful icon from the activities disc
       activity.Activity.close(self)

In retrospect, os.fork/execv would have been a better choice than os.system.

Testing

This activity was written and tested on a G1G1 laptop, build 656.

Contributing

This project really isn't big enough to warrant a full GIT or source-control setup. If you have a suggestion, or know of a way of making this system better (i.e., if it's possible to bypass the whole activity thing and still not have dangling activity icons), please let me know and I'll update the package. To contact the author, please visit http://jtolds.com/contact/

Use Cases

ExecCommand is successfully being used on XO laptops in NYC to help with manual network configuration. Check it out