sys/src/games/geigerstats.c

   1 #include <u.h>
   2 #include <libc.h>
   3
   4 enum {
   5         SRATE = 44100,
   6         NSAMP = SRATE / 10,
   7 };
   8
   9 void
  10 usage(void)
  11 {
  12         fprint(2, "%s: usage: %s [-d dev] [-v vol]\n", argv0, argv0);
  13         exits("usage");
  14 }
  15
  16 int
  17 load(void)
  18 {
  19         static int fd = -1;
  20         static char buf[1024];
  21         int rc, sum;
  22         char *p, *q, *e;
  23         char *f[10];
  24
  25         if(fd < 0)
  26                 fd = open("/dev/sysstat", OREAD);
  27         if(fd < 0)
  28                 sysfatal("open: %r");
  29         seek(fd, 0, 0);
  30         if((rc = readn(fd, buf, sizeof(buf)-1)) < 0)
  31                 sysfatal("read: %r");
  32         p = buf;
  33         e = buf + rc;
  34         sum = 0;
  35         while(p < e){
  36                 q = memchr(p, '\n', e - p);
  37                 if(q == nil)
  38                         q = e;
  39                 *q = 0;
  40                 rc = tokenize(p, f, nelem(f));
  41                 if(rc >= 7)
  42                         sum += atoi(f[7]);
  43                 p = q;
  44                 if(p < e)
  45                         p++;
  46         }
  47         return sum;
  48 }
  49
  50 void
  51 main(int argc, char **argv)
  52 {
  53         char *dev;
  54         uchar buf[4 * NSAMP], *p;
  55         short s;
  56         int vol, fd, cps;
  57         ulong tresh;
  58
  59         dev = "/dev/audio";
  60         vol = 32767;
  61         s = 0;
  62         ARGBEGIN{
  63         case 'd':
  64                 dev = strdup(EARGF(usage()));
  65                 break;
  66         case 'v':
  67                 vol = atoi(EARGF(usage()));
  68                 break;
  69         default:
  70                 usage();
  71         }ARGEND;
  72         if(argc != 0)
  73                 usage();
  74         fd = open(dev, OWRITE);
  75         if(fd < 0)
  76                 sysfatal("open: %r");
  77         for(;;){
  78                 cps = 3 + load() / 3;
  79                 tresh = umuldiv(0xFFFFFFFF, cps, SRATE);
  80                 for(p = buf; p < buf + sizeof(buf);){
  81                         s = lrand() < tresh ? (vol - s) : s;
  82                         *p++ = s;
  83                         *p++ = s >> 8;
  84                         *p++ = s;
  85                         *p++ = s >> 8;
  86                 }
  87                 if(write(fd, buf, sizeof(buf)) < 0)
  88                         sysfatal("write: %r");
  89         }
  90 }