My "Hello, OSS!" application

sndtest.c

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <stropts.h>

#include <string.h>

#include <linux/soundcard.h>
//#include <soundcard.h>

/*

gcc -Wall sndtest.c -o sndtest && ./sndtest

old:
gcc -Wall -I/usr/lib/oss/include/sys/ sndtest.c -o sndtest && ./sndtest

*/

int main(int argc, char *argv[]) {
  int tmp, tmp2, control, i, j;
  int chunklen = 16 * 1024;
  int fragsize = chunklen * 2;
  int16_t * chunk = malloc(fragsize);
  
  int dspfd;
  //oss_audioinfo ai;
  //ai.dev = -1;
  
  long long samplesWritten = 0;
  int channels = 1;
  int rate = 44100;
  int amplitude = 8000;
  int frequency = 100;
  
  if ((dspfd = open("/dev/dsp", O_WRONLY/* | O_NONBLOCK*/)) == -1) return EXIT_FAILURE;
  //if (ioctl (dspfd, SNDCTL_ENGINEINFO, &ai) == -1) return EXIT_FAILURE;
  
  //printf ("\nUsing audio engine #%d: %s\n\n", ai.dev, ai.name);
  
  tmp = channels;
  if (ioctl(dspfd, SNDCTL_DSP_CHANNELS, &tmp) == -1) return EXIT_FAILURE;
  if (tmp != channels) return EXIT_FAILURE;
  
  tmp = AFMT_S16_NE;
  if (ioctl(dspfd, SNDCTL_DSP_SETFMT, &tmp) == -1) return EXIT_FAILURE;
  
  tmp = rate;
  if (ioctl(dspfd, SNDCTL_DSP_SPEED, &tmp) == -1) return EXIT_FAILURE;
  if (tmp != rate) return EXIT_FAILURE;
  
  for (i = 0 ; 1 ; i++) {
    memset(chunk, 0, fragsize);
    for (j = 0 ; j < chunklen ; j++) {
      control = ((samplesWritten + j) % frequency) * 4 * amplitude / frequency;
      chunk[j] = control < 2 * amplitude
               ? control - amplitude
               : 3 * amplitude - control;
    }
    
    ioctl(dspfd, SNDCTL_DSP_GETODELAY, &tmp);
    if (write(dspfd, chunk, fragsize) != fragsize) return EXIT_FAILURE;
    ioctl(dspfd, SNDCTL_DSP_GETODELAY, &tmp2);
    
    samplesWritten = samplesWritten + chunklen;
    
    printf("Chunk: %3i, Delay: %5i, in s: %5.2f, II: %5i\n", i, tmp, (float)tmp / rate / 2, tmp2);
    fflush(stdout);
  }
  
  close(dspfd);
  return EXIT_SUCCESS;
};