C语言实现udp服务器端监听根据输入的ip和端口的代码

以下是使用C语言实现UDP服务器端监听根据输入的IP和端口的代码示例：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>

#define BUF_SIZE 1024

int main(int argc , char *argv[])
{
    int udp_socket;
    struct sockaddr_in server_addr, client_addr;
    char buffer[BUF_SIZE];
    int str_len, client_addr_size;

    if(argc != 3) {
        printf("Usage: %s <IP> <port>\n", argv[0]);
        exit(1);
    }

    udp_socket = socket(PF_INET, SOCK_DGRAM, 0);    
    if (udp_socket == -1)
        printf("Error: socket()\n");

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;               
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);   
    server_addr.sin_port = htons(atoi(argv[2]));          

    if (bind(udp_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1)
        printf("Error: bind()\n");

    while(1) {
        client_addr_size = sizeof(client_addr);
        str_len = recvfrom(udp_socket, buffer, BUF_SIZE-1, 0, (struct sockaddr*)&client_addr, &client_addr_size);
        if (str_len < 0)
            break;

        buffer[str_len] = '\0';
        printf("Received message from %s:%d: %s\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), buffer);

        str_len = sendto(udp_socket, buffer, str_len, 0, (struct sockaddr*)&client_addr, client_addr_size);
        if (str_len < 0)
            break;
    }

    close(udp_socket);
    return 0;
}

希望对你有帮助。