PulseAudio Tames the Linux Audio Zoo, Part 2: Page 3

PULSEAUDIO_SYSTEM_START=1
DISALLOW_MODULE_LOADING=0

That should be the opposite of the default. Then any user that needs access to the Pulse server needs to be added to the pulse-access group, including root. Then start it in the usual way:

$ sudo /etc/init.d/pulseaudio start

 * Starting PulseAudio Daemon      [ OK ]

Now when you open the PulseAudio Manager it looks like Figure 2, and aplay will play your file.

But on a multi-user system this is not the best way to run PulseAudio, according to the developers. It is better to run it per-user for these reasons: it creates a potential security hazard because it runs SUID, users can mess with other users' sound, and settings are system-wide instead of individualized. If you're on a single-user system then it doesn't matter.

If you want it to run per-user, then each user needs individual configuration and startup files. PulseAudio is already well-integrated into Gnome, and Gnome supports per-session startup, so the hard work is already done. If you're running a distribution that does not default to PulseAudio, create a symlink from Pulse's compatibility script to the ESD binary to load PulseAudio instead:

# ln -sf /usr/local/bin/esdcompat /usr/bin/esd

Verify your filepaths first, of course.

What do users of other desktop environments do? We'll get into detail on that next week. Meanwhile, KDE users can do this: stop it by running sudo /etc/init.d/pulseaudio stop, then reverse the changes to /etc/default/pulseaudio so that it does not start at boot. Then start it manually like this:

$ pulseaudio --high-priority --log-target=syslog

Check out the various userland tools, which you should find in your multimedia menu, and next week we'll learn how to configure per-user startup, learn about sinks and sources, and play networked sounds.

Resources

• SUID programs, getting to the root of the problem
• PulseAudio
• Interviews/LennartPoettering

Carla Schroder is the author of the Linux Cookbook and the newly-released Linux Networking Cookbook, and is a regular contributor to LinuxPlanet.

This article was first published on LinuxPlanet.com.