通过串行接口(interface)用c++连接到cisco路由器

Question

我想从我的 C++ 应用程序连接到 Cisco 路由器。需要它才能获取接口(interface)状态。我的linux站(Ubuntu)和路由器通过串行接口(interface)连接。

从 puty 或 minicom 或控制台连接进行连接。

例如:

root@test:/etc/minicom# cu -l /dev/ttyS0 -s 9600
Connected.

Router#show int summary

 *: interface is up
 IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
 OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
 RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
 TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
 TRTL: throttle count

现在我尝试用 C++(或 C)做同样的事情，但是读到了hang。

我的c代码:

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
#include <unistd.h>
#include <iostream>
#include<stdio.h>
#include<sys/ioctl.h>
#include<unistd.h>
#include<fcntl.h>
using namespace std;
int fd1;
int fd2;
char *buff, *buffer, *bufptr;
int wr, rd, nbytes, tries;

int configure_port(int fd)      // configure the port
        {
    struct termios port_settings;     // structure to store the port settings in
    bzero(&port_settings, sizeof(port_settings));
    cfsetispeed(&port_settings, B9600);    // set baud rates
    cfsetospeed(&port_settings, B9600);

    port_settings.c_cflag &= ~PARENB;    // set no parity, stop bits, data bits
    port_settings.c_cflag &= ~CSTOPB;
    port_settings.c_cflag &= ~CSIZE;
    port_settings.c_cflag |= CS8;

    tcsetattr(fd, TCSANOW, &port_settings);    // apply the settings to the port
    return (fd);

}
int main() {
    fd1 = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd1 == -1) {
        perror("open_port: Unable to open /dev/ttyS0 – ");
    } else {
        fcntl(fd1, F_SETFL, 0);
    }
    printf("Port 1 has been sucessfully opened and %d is the file description\n",fd1);
    configure_port(fd1);

wr = write(fd1, "\r", 1);
cout << " wr status " << wr << endl;
wr = write(fd1, "\r", 1);
cout << " wr  status " << wr << endl;
wr = write(fd1, "ena\r", 4);
cout << " wr status " << wr << endl;
wr = write(fd1, "show int sum\r", 13);
cout << " wr status " << wr << endl;
rd = read(fd1, buff, 50);
cout << " rd status " << rd << endl;
cout << rd << endl;
    return 0;
}

Answer 1

在修改 port_settings 结构之前，您没有先将其清零。这肯定是一个错误，尽管它可能不是问题的根源。您是否尝试过构建互联网上可用的数十个“termios 示例程序”之一以进行比较？