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

#define RIFF		0x46464952
#define WAVE		0x45564157
#define FMT		0x20746D66
#define DATA		0x61746164
#define PCM_CODE	1
#define WAVE_MONO	1
#define WAVE_STEREO	2

typedef struct {
    int	            riff_tag;
    int		    riff_length;
    int		    wave_tag;
    int		    fmt_tag;
    int		    fmt_length;
    unsigned short  format;
    unsigned short  channels;
    int             samp_rate;
    int		    avg_samp_rate;
    unsigned short  align;
    unsigned short  bits_per_sample;
    int		    data_tag;
    int		    data_length;
} WAVHDR;

#ifdef BIGENDIAN
/* convert the bytes of a 16-bit integer to little endian */
#define BSWAP16(c) (((c & 0xff) << 8) | ((c >> 8) & 0xff))
/* convert the bytes of a 32-bit integer to little endian */
#define BSWAP32(c) ((c>>24)&0xff)|((c>>8)&0xff00)|((c<<8)&0xff0000)|(c<<24)
#else
#define BSWAP16(c) c
#define BSWAP32(c) c
#endif


WAVHDR* read_wavhdr(int fd)
{
    static WAVHDR *wavhdr = NULL;

    if (! wavhdr)
	wavhdr = (WAVHDR*)malloc(sizeof(WAVHDR));
 
    if (read(fd, wavhdr, sizeof(WAVHDR)) == -1)
	return NULL;

    wavhdr->riff_tag = BSWAP32(wavhdr->riff_tag);
    wavhdr->riff_length = BSWAP32(wavhdr->riff_length);
    wavhdr->wave_tag = BSWAP32(wavhdr->wave_tag);
    wavhdr->fmt_tag = BSWAP32(wavhdr->fmt_tag);
    wavhdr->fmt_length = BSWAP32(wavhdr->fmt_length);
    wavhdr->format = BSWAP16(wavhdr->format);
    wavhdr->channels = BSWAP16(wavhdr->channels);
    wavhdr->samp_rate = BSWAP32(wavhdr->samp_rate);
    wavhdr->avg_samp_rate = BSWAP32(wavhdr->avg_samp_rate);
    wavhdr->align = BSWAP16(wavhdr->align);
    wavhdr->bits_per_sample = BSWAP16(wavhdr->bits_per_sample);
    wavhdr->data_tag = BSWAP32(wavhdr->data_tag);
    wavhdr->data_length = BSWAP32(wavhdr->data_length);

    return wavhdr;
}

void play_wav(char *name)
{
    WAVHDR *wavhdr;
    char *audiobuf = NULL;
    int fd = 0, audio = 0, bufsize, samplesize, stereo, speed, toread, n;
    
    if (! strlen(name))
	return;
    
    if ((audio = open("/dev/dsp", O_WRONLY)) == -1) {
	perror("DSP open");
	goto end;
    }

    if ((fd = open(name, O_RDONLY)) == -1) {
	perror("open");
	goto end;
    }
	    
    if (! (wavhdr = read_wavhdr(fd)))
	goto end;

    if ((wavhdr->riff_tag != RIFF) || (wavhdr->wave_tag != WAVE) ||
	    (wavhdr->fmt_tag != FMT) || (wavhdr->data_tag != DATA)) {
	fprintf(stderr, "Invalid WAV format\n");
	goto end;
    }

    if (wavhdr->format != PCM_CODE) {
	fprintf(stderr, "Can't play not PCM-coded WAV files\n");
	goto end;
    }

    if (wavhdr->channels > 2) {
	fprintf(stderr, "Can't play WAV files with %d channels\n",
		wavhdr->channels);
	goto end;
    }

    if (ioctl(audio, SNDCTL_DSP_GETBLKSIZE, &bufsize) == -1) {
	perror("SNDCTL_DSP_GETBLKSIZE");
	goto end;
    }

    audiobuf = (char*)malloc(bufsize);

    samplesize = (int)wavhdr->bits_per_sample;
    stereo = (wavhdr->channels == 2) ? 1 : 0;
    speed = (int)wavhdr->samp_rate;

    if (ioctl(audio, SNDCTL_DSP_SAMPLESIZE, &samplesize) == -1) {
	perror("SNDCTL_DSP_SAMPLESIZE");
	goto end;
    }

    if (ioctl(audio, SNDCTL_DSP_STEREO, &stereo) == -1) {
	perror("SNDCTL_DSP_STEREO");
	goto end;
    }

    if (ioctl(audio, SNDCTL_DSP_SPEED, &speed) == -1) {
	perror("SNDCTL_DSP_SPEED");
	goto end;
    }

    printf("Playing '%s' at %d bits, %d Hz ", name, samplesize, speed);
    if (stereo)
	printf("stereo\n");
    else
	printf("mono\n");

    toread = wavhdr->data_length;
    while (toread) {
	n = (toread > bufsize) ? bufsize : toread;
	if (read(fd, audiobuf, n) == -1) {
	    perror("read");
	    break;
	}
	if (write(audio, audiobuf, n) == -1) {
	    perror("DSP write");
	    break;
	}
	toread -= n;
    }

end:
    if (audio > 0)
	close(audio);
    if (fd > 0)
	close(fd);
    if (audiobuf)
	free(audiobuf);
}

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

    if (argc < 2) {
	fprintf(stderr, "usage: wplay <file ...>\n");
	exit(0);
    }

    for (i = 1; i < argc; i++)
	play_wav(argv[i]);

    return 0;
}
.