c_cpp Linux的下UDP的Socket的编程示例

Posted 2021-05-14

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <dirent.h>
#include <signal.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(int argc , const char* argv[])
{
    int sockfd = socket(AF_INET, SOCK_DGRAM, 0);

    struct sockaddr_in serv;
    serv.sin_family = AF_INET;
    serv.sin_port = htons(8888);
    inet_pton(AF_INET, "127.0.0.1", &serv.sin_addr.s_addr);

    char buf[256];
    int ret;
    while (1)
    {
        ret = read(STDIN_FILENO, buf, sizeof(buf));
        if (ret > 0)
        {
            sendto(sockfd, buf, ret, 0, (struct sockaddr*)&serv, sizeof(serv));

            ret = recvfrom(sockfd, buf, sizeof(buf), 0,(struct sockaddr*)NULL, NULL);
            if (ret > 0)
            {
                write(STDOUT_FILENO, buf, ret);
            }
        }
    }
    
    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <dirent.h>
#include <signal.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <ctype.h>

int main(int argc, const char* argv[])
{
    int sockfd = socket(AF_INET, SOCK_DGRAM, 0);

    struct sockaddr_in serv;
    serv.sin_family = AF_INET;
    serv.sin_port = htons(8888);
    serv.sin_addr.s_addr = INADDR_ANY;
    bind(sockfd, (struct sockaddr*)&serv, sizeof(serv));

    char buf[256];
    int ret;
    struct sockaddr_in client;
    socklen_t clen = sizeof(client);

    while (1)
    {
        ret = recvfrom(sockfd, buf, sizeof(buf),
            0, (struct sockaddr*)&client, &clen);

        if (ret > 0)
        {
            for (int i = 0;i<ret;i++)
            {
                buf[i] = toupper(buf[i]);
            }

            sendto(sockfd, buf, ret, 0, (struct sockaddr*)&client, clen);
        }

    }

    close(sockfd);
    return 0;
}