libasound-plugins/libasound-getprogname.c

   1
   2 /*
   3 DESCRIPTION
   4
   5         This libasound (ALSA) configuration plugin provides "getprogname" @func function.
   6         It enables you to have eg. a softvolume control channel for each program.
   7         When a new control is created, the client program have to stop+play or restart,
   8         otherwise the control's volume level can not be changed. Tough, it works great at
   9         the second time.
  10         The created control stays there after the program exists.
  11
  12 EXAMPLE
  13
  14         ~/.asoundrc:
  15
  16         pcm.softvol0 {
  17                 type softvol
  18                 slave.pcm "hw:0"
  19                 control {
  20                         name {
  21                                 @func getprogname
  22                                 default "SoftVolume0"
  23                         }
  24                         card hw
  25                         device 0
  26                 }
  27         }
  28
  29         func.getprogname {
  30                 lib "/usr/src/alsa-lib-1.0.25/libasound-getprogname.so"
  31                 func "snd_func_getprogname"
  32         }
  33
  34 BUILD
  35
  36         Compile against alsa-lib-1.0.25
  37
  38         if libtool acts weirdly, it may forgot that $ECHO is $echo ... or the other way around...
  39
  40
  41         # not good
  42         #gcc -Iinclude/ -lbsd libasound-getprogname.c -o libasound-getprogname.so -shared -fPIC -Wl,--version-script=libasound-getprogname.ver
  43
  44         # less wrong? it worked anyway...
  45         mkdir .libs
  46         ./libtool --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -Wall -g -I./include/  \
  47                 -D_GNU_SOURCE -g -O2  -MD -MP  -c -o libasound-getprogname.lo libasound-getprogname.c
  48         gcc -shared -lbsd -lasound .libs/libasound-getprogname.o -o libasound-getprogname.so
  49 */
  50
  51 #include <bsd/stdlib.h>
  52
  53 #include "include/local.h"
  54
  55 int snd_func_getprogname(snd_config_t **dst, snd_config_t *root ATTRIBUTE_UNUSED,
  56                      snd_config_t *src, snd_config_t *private_data ATTRIBUTE_UNUSED)
  57 {
  58         const char *id;
  59         int err = snd_config_get_id(src, &id);
  60         if (err < 0) return err;
  61
  62         char *progname = getprogname();
  63         return snd_config_imake_string(dst, id, progname);
  64 }
  65
  66 SND_DLSYM_BUILD_VERSION(snd_func_getprogname, SND_CONFIG_DLSYM_VERSION_EVALUATE);