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转载：http://blog.sina.com.cn/s/blog_6cb543ef0100x90j.html
今日编写了一个串口通讯程序，但是本机只有一个串口，无法验证程序的正确性，于是想到在linux下面增加一对虚拟串口
Python：
#! /usr/bin/env python
#coding=utf-8
import pty
import os
import select
def mkpty():
# 打开伪终端
master1, slave = pty.openpty()
slaveName1 = os.ttyname(slave)
master2, slave = pty.openpty()
slaveName2 = os.ttyname(slave)
print ‘\nslave device names: ‘, slaveName1, slaveName2
return master1, master2
if __name__ == "__main__":
master1, master2 = mkpty()
while True:
rl, wl, el = select.select([master1,master2], [], [], 1)
for master in rl:
data = os.read(master, 128)
print "read %d data." % len(data)
if master==master1:
os.write(master2, data)
else:
os.write(master1, data)
程序名叫mkptych.py，在终端里运行“python mkptych.py &”，这样就可以生成一个基于pty（伪终端）的虚拟端口对，两个设备名会显示在终端里。然后就可以利用这两个设备名在本机上进行虚拟串口之类的调试，使用完后用ps查看这个python进程的pid号，然后kill掉即可。
下面编写一个用上述虚拟串口的使用程序：
receiver.c
#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#include <math.h>
#define MAX_BUFFER_SIZE 512
int fd, s;
int open_serial()
{
//这里的/dev/pts/27是使用mkptych.py虚拟的两个串口名字之一
fd = open("/dev/pts/27", O_RDWR|O_NOCTTY|O_NDELAY);
if(fd == -1)
{
perror("open serial port error!\n");
return -1;
}
printf("open /dev/ttyS0.\n");
return 0;
}
int main()
{
char hd[MAX_BUFFER_SIZE], *rbuf;
int flag_close, retv;
struct termios opt;
retv = open_serial();
if(retv < 0)
{
printf("Open serrial port error!\n");
return -1;
}
tcgetattr(fd, &opt);
cfmakeraw(&opt);
cfsetispeed(&opt, B9600);
cfsetospeed(&opt, B9600);
tcsetattr(fd, TCSANOW, &opt);
rbuf = hd;
printf("Ready for receiving data...\n");
while(1)
{
while((retv = read(fd, rbuf, 1)) > 0)
printf( "%c ", *rbuf);
}
printf("\n");
flag_close = close(fd);
if(flag_close == -1)
printf("Close the device failure!\n");
return 0;
}
send.c
#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#define MAX_BUFFER_SIZE 512
int fd, flag_close;
int open_serial()
{
//这里的/dev/pts/28是使用mkptych.py虚拟的两个串口名字之一
fd = open("/dev/pts/28", O_RDWR | O_NOCTTY | O_NONBLOCK);
if(fd == -1)
{
perror("open serial port error!\n");
return -1;
}
printf("Open serial port success!");
return 0;
}
int main(int argc, char* argv[])
{
char sbuf[] = {"Hello, this is a serial port test!\n"};
int retv;
struct termios option;
retv = open_serial();
if(retv < 0)
{
perror("open serial port error!\n");
return -1;
}
printf("Ready for sending data...\n");
tcgetattr(fd, &option);
cfmakeraw(&option);
cfsetispeed(&option, B9600);
cfsetospeed(&option, B9600);
tcsetattr(fd, TCSANOW, &option);
int length = sizeof(sbuf);
retv = write(fd, sbuf, length);
if(retv == -1)
{
perror("Write data error!\n");
return -1;
}
printf("The number of char sent is %d\n", retv);
return 0;
}
编译运行即可，呵呵.
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原文地址：http://www.cnblogs.com/pengdonglin137/p/4513943.html
