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 1024 void 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。