alsa-utils/salsa.c

/* Copyright 2005 Red Hat, Inc.
 *
 * Portions extraced from various ALSA code:
 *  Copyright (c) by Abramo Bagnara <abramo@alsa-project.org>
 *                   Jaroslav Kysela <perex@suse.cz>
 *
 * This software may be freely redistributed under the terms of the GNU
 * public license.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <alsa/asoundlib.h>

#define ALSA_CONFIG_PATH	"/etc/asound.state"

int get_card_number()
{
  char *devname, *action;

  action = getenv("ACTION");
  if (!action || strcmp(action, "add"))
    return -1;
  devname = getenv("DEVNAME");
  if (!devname)
    return -1;
  if (!strncmp(devname, "/dev/snd/controlC", 17))
    return atoi(devname + 17);
  if (!strncmp(devname, "/dev/snd/pcmC", 13))
    return atoi(devname + 13);
  return -1;
}

int has_config(int index)
{
  int rc = 0;
  snd_config_t *config, *control;
  snd_input_t *in;
  snd_ctl_t *handle;
  snd_ctl_card_info_t *info;
  const char *id;
  char path[32];

  rc = snd_config_top(&config);
  if (rc < 0)
    goto out;
  rc = snd_input_stdio_open(&in, ALSA_CONFIG_PATH, "r");
  if (rc >= 0) {
    rc = snd_config_load(config, in);
    snd_input_close(in);
    if (rc < 0)
      goto out;
  }
  sprintf(path, "hw:%d", index);
  rc = snd_ctl_open(&handle, path, 0);
  if (rc < 0)
    goto out;
  snd_ctl_card_info_alloca(&info);
  rc = snd_ctl_card_info(handle, info);
  if (rc < 0)
    goto out_close;
  id = snd_ctl_card_info_get_id(info);
  rc = snd_config_searchv(config, &control, "state", id, "control", 0);
out_close:
  snd_ctl_close(handle);
out:
  return !rc;

}

int run_alsactl(int index)
{
  char *args[] = { "/sbin/alsactl", "restore", NULL, NULL };
  char num[10];

  sprintf(num, "%d", index);
  args[2] = num;
  execv(args[0], args);
  return 1;
}

void frob_mixer(int index)
{
  char tmp[100];  
  snprintf(tmp, 100, "%d", index);
  tmp[99] = '\0';
  execl("//usr//bin//alsaunmute","//usr//bin//alsaunmute", tmp, "-v", NULL);
}

int main(int argc, char **argv)
{
  int i;

  i = get_card_number();
  if (i < 0)
    return 0;
  if (has_config(i))
    return run_alsactl(i);
  else
    frob_mixer(i);
  
  return(0);
}