conf: Allow for a directory to be given as a config file.

When this is done, *.conf files can be placed in that directory and they
will be processed by as if they were included directly.

A directory (typically /usr/share/alsa/alsa.conf.d/) has been
added into the distribution.

v2: Used existing conf syntax rather than processing via autotools
v3: Split file loading into separate function and made error handling
more consistent.

Signed-off-by: Colin Guthrie <colin@mageia.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

src/conf/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS=cards pcm
+SUBDIRS=cards pcm alsa.conf.d
 
 cfg_files = alsa.conf
 if BUILD_ALISP

src/conf/alsa.conf

@@ -8,6 +8,13 @@
 	{
 		func load
 		files [
+			{
+				@func concat
+				strings [
+					{ @func datadir }
+					"/alsa.conf.d/"
+				]
+			}
 			"/etc/asound.conf"
 			"~/.asoundrc"
 		]

src/conf/alsa.conf.d/Makefile.am

@@ -0,0 +1,8 @@
+alsaconfigdir = @ALSA_CONFIG_DIR@
+alsadir = $(alsaconfigdir)/alsa.conf.d
+cfg_files = README
+
+alsa_DATA = $(cfg_files)
+
+EXTRA_DIST = \
+	$(cfg_files)

src/conf/alsa.conf.d/README

@@ -0,0 +1,2 @@
+You can place files named *.conf in this folder and they will be processed
+when initialising alsa-lib.