Datasheet

15
Sound in Linux
for i in ‘pidof timidity‘; do setpriority $i fifo 10; done
Running a program in root mode is always risky, as the program is permitted to
do anything. If the computer is connected to the Internet, the security risk would
be unacceptable. Security bugs in the program could be exploited for the purpose
of gaining access to the system.
Caution
The commands described in the following paragraphs should never
be executed on machines that can be accessed from the Internet or if a
system crash or data loss would have serious consequences.
Caution
The sudo mechanism should be used for running a program in root mode. This
mechanism is demonstrated by means of the timidity++ application. To enable all
users on your system to execute timidity++ with root privileges, modify the file
/etc/sudoers. See sudo and sudoers for the procedure. If you are not famil-
iar with vi, select a different editor, such as joe, by exporting the desired editor,
for example, with the command export EDITOR=joe. Then execute visudo as
root and append the following line at the end of the file /etc/sudoers:
ALL ALL=(ALL) /usr/bin/timidity
Now all system users are permitted to run timidity++ in root mode with the
command sudo timidity. The password of the respective user is requested
if more than five minutes passed since the last sudo command.
15.5 The JACK Audio Connection Kit
Using the JACK Audio Connection Kit (packages named jack and
qjackconnect), applications can exchange audio data with each other and with
the sound card. This is only possible if the respective application has a JACK in-
terface. JACK support has become a standard feature, so there are many applica-
tions that have the needed interface.
To use JACK, either start the graphical front-end QJackCtl or start the engine
from the command line with jackd -d alsa -d hw:0. JACK was designed
187SUSE LINUX