C语言从以太网口接收数据

Question

我想通过 c 程序从以太网端口访问可用数据。 因此，任何人请帮助我提供任何简单的“C”源代码，用于从以太网端口获取数据。

谢谢

Answer 1

我刚刚创建了 2 个程序来展示使用套接字进行客户端/服务器通信的最低要求。您可以通过谷歌搜索每个函数来了解它们的原型及其工作原理。

这是：

最小服务器 (minser.c)

/*
Program: minser.c
Author: Dr Beco, 2011-04-03
Objective:
    show a minimum server program that can
    create a socket, accept a client, read a byte, write a byte, disconnect
*/

#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/un.h>

#define BUFFER 2

int main(void)
{
    printf("Configuring environment... ");

    int p = 3333; // port
    char data[BUFFER];
    struct sockaddr_in dir;
    struct sockaddr client;
    socklen_t long_client;
    int id, idReuse=1, son, aux;

    memset(&dir,0,sizeof(dir));
    dir.sin_port = p;
    dir.sin_family = AF_INET;
    dir.sin_addr.s_addr = INADDR_ANY;
    printf("done!\n");

    printf("Creating socket... ");
    id = socket(AF_INET, SOCK_STREAM, 0);
    if (id == -1)
        return -1;
    printf("done!\n");

    printf("Configuring socket... ");
    if(setsockopt(id,SOL_SOCKET,SO_REUSEADDR,&idReuse,sizeof(idReuse))==-1)
       return -1;
    printf("done!\n");

    printf("Binding... ");
    if(bind(id, (struct sockaddr *)&dir, sizeof(dir)) == -1)
    {
        close (id);
        return -1;
    }
    printf("done!\n");

    printf("Listening... ");
    if (listen(id , 1) == -1)
    {
        close(id);
        return -1;
    }
    printf("done!\n");

    printf("Accepting... ");
    long_client = sizeof (client);
    son = accept(id, &client, &long_client);
    if (son == -1)
        return -1;
    printf("done!\n");

    printf("Reading... ");
    aux = read(son, data , 1);
    if(aux!=1)
        return -1;
    printf("\"%c\" ", data[0]);
    printf("done!\n");

    printf("Writing \"S\"... ");
    aux = send(son, "S", 1, MSG_NOSIGNAL);
    if(aux < 0)
        return -1;
    printf("done!\n");

    return 0;
}

最小客户端 (mincli.c)

/*
Program: mincli.c
Author: Dr Beco, 2011-04-03
Objective:
    show a minimum client program that can
    connect to a network, write a byte, read a byte, disconnect
*/

#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <netdb.h>

#define BUFFER 2

int main(void)
{
    printf("Configuring environment... ");

    char data[BUFFER];
    const char *host_server="localhost";
    struct sockaddr_in dir;
    struct hostent *host;
    int aux, id, p=3333; //port

    dir.sin_port = p;
    dir.sin_family = AF_INET;
    host = gethostbyname(host_server);
    if(host == NULL)
        return -1;
    dir.sin_addr.s_addr = ((struct in_addr *)(host->h_addr))->s_addr;
    printf("done!\n");

    printf("Creating socket... ");
    id = socket(AF_INET, SOCK_STREAM, 0);
    if(id == -1)
        return -1;
    printf("done!\n");

    printf("Connecting... ");
    if(connect(id, (struct sockaddr *)&dir, sizeof(dir)) == -1)
        return -1;
    printf("done!\n");

    printf("Writing \"C\"... ");
    aux = send(id, "C", 1, MSG_NOSIGNAL);
    if(aux < 0)
        return -1;
    printf("done!\n");

    printf("Reading... ");
    aux = read(id, data , 1);
    if(aux!=1)
        return -1;
    printf("\"%c\"", data[0]);
    printf(" done!\n");
    return 0;
}

小心，
贝科

Answer 2

您可以使用 recv() 函数。