comtest.c

Linux 串口编程(经过验证的代码） 强烈推荐

/* ************************************************************
 *
 *  comTest.c -- linux serial port test procedure source
 *
 *  author: mark wang
 *  
 *  written: 2008/05/22
 *
 *  e-mail: [e-mail]
 *
 * ************************************************************ */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/io.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <termio.h>
#include <time.h>
#include <signal.h>

void stopKey(int fd)
{
	char c;
	while(1)
	{
		scanf("%c",&c);
		if(c=='0')
		{
			close(fd);
			break;
		}
	}
	exit(0);	
}

int main(int argc, char *argv[])
{
	int fd;
	char buf[256];
	int pre;
	pthread_t id;

	struct termios opt, newOpt;
	int ret;
	int status;
	int nread,nwrite;


	if(argc!=2)
	{
		printf("usage: %s devName\n", argv[0]);
		printf("examp: %s /dev/ttyS0\n", argv[0]);
		return(1);
	}
	
	if((fd=open(argv[1], O_RDWR|O_NOCTTY/*|O_NDELAY*/))<0)
	{
		perror("Error opening the port\n");
	}
	else
	{
		printf("Succeed opening the port with fd = %d\n",fd);
	}

	tcgetattr(fd, &opt);
	tcgetattr(fd, &newOpt);

	newOpt.c_cflag |= (CLOCAL | CREAD);
	newOpt.c_cflag &= ~CBAUD;
	newOpt.c_cflag |= (B115200 | CS8); 

        newOpt.c_lflag &= ~(ICANON | ISIG | NOFLSH);
	
	newOpt.c_lflag &= ~(ECHO);
	
	newOpt.c_lflag &= ~(ECHOE);
	

	newOpt.c_oflag &= ~(OPOST | ONLCR | OCRNL);

        newOpt.c_cc[VMIN]=100;
	newOpt.c_cc[VTIME]=2;
	
	tcflush(fd,TCIFLUSH);
	
	ret = tcsetattr(fd, TCSANOW, &newOpt);
	if(ret<0)
	{
		perror("Error when tesetattr serial port\n");
		exit(1);
	}
	

	pre = pthread_create(&id,NULL,(void *)stopKey,fd);

	if(pre!=0)
	{
		perror("Error creating the stopKey pthread\n");
		exit(1);
	}

	while(1)
	{
                nread=0;
                nwrite=0;
		bzero(buf,sizeof(buf));
		nread = read(fd, buf, 255);
		printf(":::::: %d bytes received\n", nread);
                buf[nread]='\0';
                printf("%s\n",buf);
		nwrite = write(fd, buf, nread);
		printf("|||||| %d bytes sended\n", nwrite);
	}
	close(fd);
}