c++ - Linux无法使用rs232接口(interface)连接设备，Windows没有问题

Question

当使用 script+c/c++ 套接字程序通过 IP 连接到设备转换器时，这似乎可以在 Windows 7 中工作。然而，在 Linux 环境中编译的同一程序无法发送产生输出的命令。命令是 FF€，末尾的欧元符号是\x80，表示设备 EOT。

我的 Windows 笔记本电脑很可能使用 cp1252(或 Windows-1252)转换，该转换使用扩展 ASCII\80 生成欧元符号。设备供应商表示，命令的最后一个符号被编程为与 ASCII 的第一个符号不同，并且已被编程为“欧元”符号。在我的 C++ 程序中，我使用了 locale 来设置环境，但仍然没有解决。能给点建议吗？

#include <iostream>
#include <cstring>      // Needed for memset
#include <sys/socket.h> // Needed for the socket functions
#include <netdb.h>      // Needed for the socket functions
#include <unistd.h>
#include <string.h>
#include <cctype>
#include <clocale>

using namespace std;


int main(int argc, char *argv[])
{
//std::setlocale(LC_ALL, "en_US.utf-8");
//std::setlocale(LC_ALL, "en_US.iso88591");
//std::setlocale(LC_ALL, "en_US.UTF-8");
//printf ("Locale is: %s\n", setlocale(LC_ALL,"de_DE.iso88591") );
    int status;
    char* ip=argv[1];
//cout<<"hello ip:"<<&ip<<"\n";
    char* po=argv[2];
//cout<<"hello port"<<po<<"\n";
    char* co=argv[3];
//cout<<"hello "<<co<<"\n";

    struct addrinfo host_info;       // The struct that getaddrinfo() fills up with data.
    struct addrinfo *host_info_list; // Pointer to the to the linked list of host_info's.

    // The MAN page of getaddrinfo() states "All  the other fields in the structure pointed
    // to by hints must contain either 0 or a null pointer, as appropriate." When a struct
    // is created in c++, it will be given a block of memory. This memory is not nessesary
    // empty. Therefor we use the memset function to make sure all fields are NULL.
    memset(&host_info, 0, sizeof host_info);

//    std::cout << "Setting up the structs..."  << std::endl;
//   std::cout << "Das ist es ip"<<&ip;
//   std::cout << "Das ist der zweite<<&po;

    host_info.ai_family = AF_UNSPEC;     // IP version not specified. Can be both.
    host_info.ai_socktype = SOCK_STREAM; // Use SOCK_STREAM for TCP or SOCK_DGRAM for UDP.

    // Now fill up the linked list of host_info structs with google's address information.
    status = getaddrinfo(ip, po, &host_info, &host_info_list);                  // handelt die generierung und verbindung zum socket (egal ob IPv4 or IPv6) return 0 if successful
   // getaddrinfo returns 0 on succes, or some other value when an error occured.
    // (translated into human readable text by the gai_gai_strerror function).
    if (status != 0)  std::cout << "getaddrinfo error" << gai_strerror(status) ;


//    std::cout << "Creating a socket..."  << std::endl;
    int socketfd ; // The socket descripter
    socketfd = socket(host_info_list->ai_family, host_info_list->ai_socktype,
                      host_info_list->ai_protocol);                                             //generiere socket und gibt -1 bei fehler
    if (socketfd == -1)  std::cout << "socket error " ;


//    std::cout << "Connect()ing..."  << std::endl;
    status = connect(socketfd, host_info_list->ai_addr, host_info_list->ai_addrlen);            //verbinde zum server und gibt -1 bei fehler
    if (status == -1)  std::cout << "connect error" ;


//    std::cout << "send()ing message..."  << std::endl;
//    const char* co2="\xe2\x82\xac";
    //const char* co2="\x0D";
//    const char* co2="\x80\b\x04^D\x0d^M\n\v\f";
    //int ne=128;
    //char c=(char) ne;
    //char* co2=&c;
    const char* co2="\x80";
    cout<<"Das ist das EOT Zeichen\n"<<co2;

    char* msg=new char[strlen(co)+strlen(co2)+1];
    strcpy(msg,co);
    strcat(msg,co2);
    std::cout <<"\nThis is what the command is:\t" <<msg<<"\n";
    //char str[80];
    //strcpy(str,co);
    //strcat(str,co2);
    //std::cout <<"\nThis is what the command is:\t" <<str <<"\n";
    int len;
    ssize_t bytes_sent;
    len = strlen(msg);
    bytes_sent = send(socketfd, msg, len, 0);                                                   //sende und empfange daten
//    std::cout << "Waiting to recieve data..."  << std::endl;
    ssize_t bytes_recieved;
    char incomming_data_buffer[10000];
    bytes_recieved = recv(socketfd, incomming_data_buffer,10000, 0);                            //Empfange daten in speicher und mache mit programm weiter falls keine daten geschickt werden
    // If no data arrives, the program will just wait here until some data arrives.
    if (bytes_recieved == 0) std::cout << "host shut down." << std::endl ;
    if (bytes_recieved == -1)std::cout << "recieve error!" << std::endl ;
//    std::cout << bytes_recieved << " bytes recieved :" << std::endl ;
    incomming_data_buffer[bytes_recieved] = '\0' ;
    std::cout << incomming_data_buffer << std::endl;
//    std::cout << "Receiving complete. Closing socket..." << std::endl;
//    sleep (2);
    freeaddrinfo(host_info_list);                                                               //free memory
    close(socketfd);                                                                            //schliesse socket
}

Answer 1

(仅适用于 Linux)如果您需要查看 send() 发送的内容的十六进制转储，请插入以下代码:

FILE *f = popen( "od -Ax -tx1z -v", "w");
fwrite( msg, 1, len, f); 
fclose(f);

重复查看返回结果:

f = popen( "od -Ax -tx1z -v", "w");
fwrite( incomming_data_buffer, 1, bytes_recieved, f); 
fclose(f);

在 Windows 上，您只需要执行一个循环:

for (int i=0; i < len; i++) { printf("%02x ", msg[i]; } printf("\n");

[作为获取格式的答案发布]