com0t.c

非阻塞方式的COM0的驱动

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>


#define BUFSIZE 1000
             
int  main(void)
{
	FILE *fp;
    	int fd,result;
   	int i=0;
//   	char read_buf[BUFSIZE];
	char write_buf[BUFSIZE]; //={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p'};

//    	int read_count=BUFSIZE;
    	int write_count=BUFSIZE;
    /*
    Open modem device for reading and writing and not as controlling tty
    because we don't want to get killed if linenoise sends CTRL-C.
  */
   	fd = open("/dev/uart0", O_RDWR | O_NOCTTY | O_NDELAY);
   	if (fd < 0){
     		printf("Error in open COM0\n");
	     	exit(-1); 
     	}
//	printf("open ok\n");

	if((fp=fopen("/home/boa.conf", "r"))==NULL){
		printf("cannot open file boa.conf\n");
		return 0;
	}
	if(fread(&write_buf, BUFSIZE, 1, fp)!=1){
		printf("file boa.conf read error\n");
		return 0;
	}
	fclose(fp);
//	write_buf[BUFSIZE-1]='\0';
//	printf("write:\n%s\n\n", write_buf);

	while(write_count!=0){
#if 0
		if(read_count!=0){
			result=read(fd, &read_buf[BUFSIZE-read_count], read_count);
			read_count-=result;
		}
#endif
#if 1
		result=write(fd,&write_buf[BUFSIZE-write_count],write_count);
		write_count-=result;
#endif
	}
	close(fd);
#if 0
	printf("read:\n");
	for(i=0;i<BUFSIZE;i++){
		printf("%c", read_buf[i]);
	}
	printf("\n");
//	printf("write:\n%s\n\n", write_buf);
#endif
    	return 0;
}