#include <unistd.h>#include <fcntl.h>#include <sys/types.h>#include <sys/stat.h>#include <unistd.h>#include <stdlib.h>#include <stdio.h>#include <linux/soundcard.h>#define Audio_Device "/dev/dsp"/*  the following feature will be different according to different sound file,  use file command to get detail information about the wave file*/#define Sample_Size 32  /*there're two kinds of bits, 8 bits and 16 bits */#define Sample_Rate 220050 /* sampling rate */int play_sound(char *filename){  struct stat stat_buf;  unsigned char *buf = NULL;  int handler,fd;  int result;  int arg,status;/*  open the sound file and get related information,read the whole file   into the buffer memory*/  fd = open(filename, O_RDONLY);  if (fd<0)      return -1;  if (fstat(fd, &stat_buf)) {     close(fd);     return -1; }  if (!stat_buf.st_size) {	close(fd);	return -1;  }  buf = malloc(stat_buf.st_size);  if (!buf) {	close(fd);	return -1;  }  if (read(fd, buf, stat_buf.st_size) < 0) {	free(buf);	close(fd);	return -1;  } /*  open the sound card device and set the sound card hardware options */  handler = open(Audio_Device, O_WRONLY);  if (handler == -1) {	perror("open Audio_Device fail");	return -1; }   arg=Sample_Rate;  status=ioctl(handler,SOUND_PCM_WRITE_RATE,&arg);  if(status==-1){        perror("error from SOUND_PCM_WRITE_RATE ioctl");        return -1;}  arg=Sample_Size;  status=ioctl(handler,SOUND_PCM_WRITE_BITS,&arg);  if(status==-1){	  perror("error from SOUND_PCM_WRITE_BITS ioctl");	  return -1;  }  result=write(handler,buf,stat_buf.st_size);  if(result==-1){       perror("Fail to play the sound!");       return -1;  }  free(buf);  close(fd);  close(handler);  return result;}void main(void){  play_sound("/home/program/a.mp3");}