Ten minute hacks: Process pause & resume

I’m old school and still rocking an old X220 laptop because I didn’t like the new ones. My battery life isn’t as great as I’d like it to be, but it gets worse when some “webapp” (which I’d much rather have as a native GTK+ app) causes Firefox to rev my CPU with their websocket (hi gmail!) poller.

This seems to happen most often on planes or when I’m disconnected from the internet. Since it’s difficult to know which tab is the offending one, and since I might want to keep that tabs state anyway, I decided to write a little shell script to pause and resume misbehaving processes.

After putting it into my ~/bin/ and running chmod u+x ~/bin/pause-continue.sh on it, you can now:

james@computer:~$ pause-continue.sh firefox
Stopping 'firefox'...
[press any key to continue]
Continuing 'firefox'...
james@computer:~$ echo $?        # error codes work iirc

The code is trivially simple, with an added curses hack to make this 13% more fun. It sends a SIGSTOP signal initially, and then when you press a key it resumes it with SIGCONT. Here it is the code.

You should obviously substitute in the name of the process that you’d like to pause and resume. If your process breaks because it didn’t deal well with the signals, then you get to keep both pieces!

This should help me on my upcoming travel! I’ll be presenting some of my mgmtconfig work at DevConf.cz, FOSDEM and CfgMgmtCamp.eu! CfgMgmtCamp will also have a short mgmt track (looking forward to seeing Felix present!) and we’ll be around to hack on the 8th during fringe (the day after the official camp) if you’d like help to get your patch merged! I’m looking forward to it!

Happy hacking!


Upcoming speaking

I’ve got a few upcoming speaking engagements. If you’ll be attending one of these events, come see me or any of the other excellent speakers!

Please remember to check the official schedules in case there are any changes!

I’ll be speaking at the Brussels CentOS Dojo:

Automated Infrastructure Testing with Oh-My-Vagrant
…and the CentOS CI

Time/date unconfirmed: I’ll be showing some CI tricks, and showing you how the CentOS CI is the perfect CI for multi-machine test environments.


I’ll be speaking at FOSDEM:

TL;DR on legal strategy for commercial ventures
An abridged review of legal strategy and licensing issues for commercial ventures and enterprises

30/Jan/2016 (Saturday) @ 18:00: I’ll be giving my first ever “legal” talk!


Oh, My! Oh-My-Vagrant (with live demos!)
Oh-My-Vagrant development environments for hackers

31/Jan/2016 (Sunday) @ 16:30: A short Oh-My-Vagrant talk with a few live demos.


I’ll be speaking at Config Management Camp:

Next Generation Config Mgmt
A prototype for a next generation config management tool, and the specific problems this design solves.

02/Feb/2016 (Tuesday) @ 11:00: I’ll be introducing my magnum opus for 2016. Particularly excited about this presentation.


I’ll be speaking at DevConf.cz:

Next Generation Config Mgmt
A prototype for a next generation config management tool, and the specific problems this design solves.

06/Feb/2016 (Saturday) @ 14:00: I’ll be repeating the same presentation from Config Management Camp, but with renewed enthusiasm!


If you want to hack on something or talk about tech, I’ll be at the above mentioned events, so feel free to ping me or contact me.