audio/darkice: Added optional realtime capabilities.

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

audio/darkice/README

@@ -27,4 +27,11 @@ DarkIce can send the encoded stream to the following streaming servers:
  - Darwin Streaming Server
  - archive the encoded audio in files
 
+Note:
+This package optionally uses POSIX filesystem capabilities to execute with
+elevated privileges (required for realtime audio processing). This
+may be considered a security/stability risk. Please read
+http://www.slackbuilds.org/caps/ for more information. To enable
+capabilities, pass SETCAP=yes to the script.
+
 Optional dependencies: lame, opus, faac, twolame, jack-audio-connection-kit, pulseaudio

audio/darkice/darkice.SlackBuild

@@ -25,7 +25,7 @@
 
 PRGNAM=darkice
 VERSION=${VERSION:-1.2}
-BUILD=${BUILD:-1}
+BUILD=${BUILD:-2}
 TAG=${TAG:-_SBo}
 
 if [ -z "$ARCH" ]; then
@@ -96,5 +96,13 @@ for i in $( find $PKG/usr/man -type l ) ; do ln -s $( readlink $i ).gz $i.gz ; r
 mkdir $PKG/install
 cat $CWD/slack-desc > $PKG/install/slack-desc
 
+# Only add capability stuff if not disabled:
+if [ "${SETCAP:-no}" = "yes" ]; then
+  cat $CWD/setcap.sh >> $PKG/install/doinst.sh
+  # Only allow execution by audio group
+  chown root:audio $PKG/usr/bin/darkice
+  chmod 0750 $PKG/usr/bin/darkice
+fi
+
 cd $PKG
 /sbin/makepkg -l y -c n $OUTPUT/$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.${PKGTYPE:-tgz}

audio/darkice/setcap.sh

@@ -0,0 +1 @@
+[ -x /sbin/setcap ] && /sbin/setcap cap_ipc_lock,cap_sys_nice=ep usr/bin/darkice