C语言实现udp

udp_server.c

#include <stdio.h>
#include <strings.h>
#include "arpa/inet.h"

void udp_server() {
    printf("%s\n","in udp server");
    int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock_fd < 0) {
        perror("");
    }
    //绑定
    //
    struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(9090);
    //绑定自己本机的ip
//    inet_pton(AF_INET,"192.168.127.129",&addr.sin_addr.s_addr);
    addr.sin_addr.s_addr = INADDR_ANY; //通配地址
    int ret=bind(sock_fd,(struct sockaddr*)&addr,sizeof(addr));
    if(ret<0){
        perror("");
    }
    struct sockaddr_in cli_addr;
    socklen_t  len = sizeof(cli_addr);
    while (1){
        char buf[128]="";
        int n = recvfrom(sock_fd,buf, sizeof(buf),0,(struct sockaddr*)&cli_addr, &len);
        printf("%s\n",buf);
        sendto(sock_fd,buf,n,0,(struct sockaddr*)&cli_addr, sizeof(cli_addr));
    }
}


int main() {
    udp_server();
    return 0;
}

udp_client.c

#include <stdio.h>
#include <strings.h>
#include "arpa/inet.h"
void client(){
    //ipv4的套接字结构体
    struct sockaddr_in server_addr;
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(9090);//转大端，这是目标机器的port
    inet_pton(AF_INET, "10.13.168.224", &server_addr.sin_addr.s_addr);
    // 创建套接字
    int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock_fd < 0) {
        perror("");
    }
    while (1) {
        char buf[128] = "";
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf) - 1] = 0;
        sendto(sock_fd, buf, strlen(buf), 0, (struct sockaddr *) &server_addr, sizeof(server_addr));
        char read_buf[128] = "";
        recvfrom(sock_fd, read_buf, sizeof(read_buf), 0, NULL, NULL);
        printf("%s\n", read_buf);
    }
}
int main() {
    client();
    return 0;
}