I want to add the Apache user (www-data) to the audio group. I've read the man page for useradd, but I'm not having any luck. I'm running xubuntu 11.10. Here's what I'm doing:
$ sudo useradd -G audio www-data useradd: user 'www-data' already exists
If I leave out the -G option, bash, prints the help info for useradd:
$ sudo useradd audio www-data Usage: useradd [options] LOGIN Options: -b, --base-dir BASE_DIR base directory for the home directory...
It's not clear to me from the man page what options I should select to make this work.