udp socket服务端客户端示例

来源：互联网发布：工农兵大学生知乎编辑：程序博客网时间：2024/05/09 08:31

创建UDP服务端监听

客户端发送数据

服务端

#include <stdio.h>#include <sys/select.h>#include <unistd.h>#include <sys/types.h>#include <sys/socket.h>#include <arpa/inet.h>#include <string.h>#include <stdlib.h>#define PORT 12345#define BUF_SIZE 65536voidbuf_dump(char *buf, int len){#define PER_LINE 32printf("--------------------------------\n");int i;for (i = 0; i < len; i++) {printf("%02x ", (unsigned char)buf[i]);if (((i + 1) % PER_LINE) == 0) {printf("\n");}}printf("\n--------------------------------\n");#undef PER_LINE}intmain(void){printf("server start\n");int ret = -1;int sockfd = -1;sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (sockfd < 0) {perror("socket()");}struct sockaddr_in server_addr;memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_port = htons(PORT);server_addr.sin_addr.s_addr = htons(INADDR_ANY);ret = bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr));if (ret < 0) {perror("bind()");}int max_fd = sockfd + 1;fd_set rfds;char buf[BUF_SIZE];int n = 0;while (1) {FD_ZERO(&rfds);FD_SET(sockfd, &rfds);ret = select(max_fd, &rfds, NULL, NULL, NULL);if (ret > 0) {if (FD_ISSET(sockfd, &rfds)) {memset(buf, 0, sizeof(buf));n = recvfrom(sockfd, buf, sizeof(buf), 0, NULL, NULL);if (n > 0) {buf_dump(buf, n);} else {perror("recvfrom()");}}} else {perror("select()");}}return 0;}

客户端

#include <stdio.h>#include <sys/select.h>#include <unistd.h>#include <sys/types.h>#include <sys/socket.h>#include <arpa/inet.h>#include <string.h>#define PORT 12345#define BUF_SIZE 65536intmain(void){printf("client start\n");int ret = -1;int sockfd = -1;sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (sockfd < 0) {perror("socket()");}struct sockaddr_in server_addr;memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_port = htons(PORT);server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");while (1) {ret = sendto(sockfd, "hello", 5, 0, (struct sockaddr *)&server_addr, sizeof(server_addr));if (ret < 0) {perror("sendto()");}sleep(2);}return 0;}