#include<stdio.h>#include<sys/types.h>#include<sys/stat.h>#include<fcntl.h>#include<unistd.h>int main(void){  char *str;  int dev,i=0;  dev=open("/dev/lcd_driver",O_WRONLY|O_NDELAY); if(dev==-1){  printf("open() failed!\n");  exit(-1); } printf("please input :\n"); while((*(str+i)=getchar())!='!')  {    i++;  } write(dev,str,strlen(str));   close(dev); printf("succeed\n"); return 0;}