#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <sys/soundcard.h>

int getvolume()
{ 
  int fd;
  int vol=-1;
  if ((fd = open ("/dev/mixer", O_RDONLY))<0) return -1;
  if((ioctl(fd,SOUND_MIXER_READ_PCM, &vol)) < 0) perror("Volume");
  close(fd);
  return vol;
}

char setvolume(int vol)
{ 
  int fd;
  if ((fd = open ("/dev/mixer", O_WRONLY))<0) return -1;
  if((ioctl(fd,SOUND_MIXER_WRITE_PCM, &vol)) < 0) perror("Volume");
  close(fd);
  return 0;
}

void printusage(char* name)
{
  printf("%s v. 0.9\n",name);
  return;
}

int main(int argc, char **argv)
{
  int vol=-1,help;
  char ch;
  extern char *optarg;

  if (argc<2)
  {
    printusage(argv[0]);
    return -1;
  }
  while ((ch=getopt(argc,argv,"r:s:"))!=-1)
    switch (ch)
    {
      case 's':
        vol=atoi(optarg);
        vol|=vol<<8;
        break;
      case 'r':
        vol=atoi(optarg);
        vol=(vol<0?-1:1)*(abs(vol)+(abs(vol)<<8));
        help=getvolume();
        if (vol<0 && vol+help<0) {vol=0; break;}
        if (vol>0 && vol+help>0x6464) {vol=0x6464; break;}
        vol+=help;
        break;
      default:
        printusage(argv[0]);
        return -1;
    }

  if (vol==-1)
  {
    vol=atoi(argv[1]);
    vol|=vol<<8;
  }
  if (setvolume(vol)) return 0; else return 1;
}