FAQ025

From the ALSA wiki

ALSA utilities don't work unless I'm root on my Linux system. Why is that?

Your files probably have incorrect permissions. The device files in /dev/snd need to be user-readable and user-writable (the tool alsactl is only meant to be run by root though).

Here's the output of ls /dev/snd -l on my system:

  tapas@mango:~$ ls /dev/snd/ -l
  total 0
  crw-rw---    1 root     audio    116,   0 Nov 17 04:32 controlC0
  crw-rw---    1 root     audio    116,  32 Nov 17 04:32 controlC1
  crw-rw---    1 root     audio    116,  64 Nov 17 04:32 controlC2
  crw-rw---    1 root     audio    116,  96 Nov 17 04:32 controlC3
  crw-rw---    1 root     audio    116,   4 Nov 17 04:32 hwC0D0
  crw-rw---    1 root     audio    116,   5 Nov 17 04:32 hwC0D1
  crw-rw---    1 root     audio    116,   6 Nov 17 04:32 hwC0D2
  ... etc ...

In this setup, I, as the user belong to the group audio and therefore have read-write access (shown by rw above) to the ALSA device files. You can use the command groups to see which groups you belong to:

  tapas@mango:~$ groups 
  tapas cdrom audio wheel priv

Read this page for general linux/unix help:

http://www.tldp.org/

and especially: http://www.tldp.org/LDP/intro-linux/html/chap_03.html

Look for unix/linux introductory guides to know more about filesystems and how to set change permissions. If this is too much for you and you just want a quick hack which disregards all security concerns, you can just do [as root]:

  chmod a+rw /dev/snd/*