#!/bin/sh
#
# Get the supplementary group ID(s) needed to access sound device.  These are
# added to the ones provided by $SUP_GROUP_IDS.
#

set -e # Exit immediately if a command exits with a non-zero status.
set -u # Treat unset variables as an error.

SND_DEV="/dev/snd"

SUP_GROUP_IDS="${SUP_GROUP_IDS:-}"

# Add group associated to the sound device.
if [ -d "$SND_DEV" ]; then
    # Save the associated group.
    SND_GRP="$(find "$SND_DEV" -maxdepth 1 -not -type d -exec stat -c "%g" {} \; | sort -u | tail -n1)"

    if [ -n "$SUP_GROUP_IDS" ]; then
        SUP_GROUP_IDS="$SUP_GROUP_IDS,$SND_GRP"
    else
        SUP_GROUP_IDS="$SND_GRP"
    fi
fi

echo "$SUP_GROUP_IDS" | tr ',' '\n'

# vim:ft=sh:ts=4:sw=4:et:sts=4