linux系统下udp编程实例

以下是一个简单的UDP编程实例，用于在Linux系统上发送和接收UDP数据包。

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#define BUF_SIZE 1024void error_handling(char *message);int main(int argc, char *argv[]) {int sock;char message[BUF_SIZE];int str_len;socklen_t adr_sz;struct sockaddr_in serv_adr, from_adr;if (argc != 3) {printf("Usage: %s <IP> <port>\n", argv[0]);exit(1);}sock = socket(PF_INET, SOCK_DGRAM, 0);if (sock == -1)error_handling("socket() error");memset(&serv_adr, 0, sizeof(serv_adr));serv_adr.sin_family = AF_INET;serv_adr.sin_addr.s_addr = inet_addr(argv[1]);serv_adr.sin_port = htons(atoi(argv[2]));while (1) {fputs("Input message(Q to quit): ", stdout);fgets(message, BUF_SIZE, stdin);if (!strcmp(message, "q\n") || !strcmp(message, "Q\n"))break;sendto(sock, message, strlen(message), 0, (struct sockaddr *)&serv_adr, sizeof(serv_adr));adr_sz = sizeof(from_adr);str_len = recvfrom(sock, message, BUF_SIZE, 0, (struct sockaddr *)&from_adr, &adr_sz);message[str_len] = 0;printf("Message from server: %s", message);}close(sock);return 0;}void error_handling(char *message) {fputs(message, stderr);fputc('\n', stderr);exit(1);}

编译和运行：

$ gcc udp_client.c -o udp_client$ ./udp_client <IP> <port>

其中，<IP>和<port>是UDP服务器的IP地址和端口号。