LINUX下c语言SOCKET客户端示范
#include <netinet/in.h> // for sockaddr_in #include <sys/types.h> // for socket #include <sys/socket.h> // for socket #include <stdio.h> // for printf #include <stdlib.h> // for exit #include <string.h> // for bzero /* #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> */ #define SERVER_PORT 6666 #define BUFFER_SIZE 1024 #define FILE_NAME_MAX_SIZE 512 int main(int argc, char **argv) { if (argc != 2) { printf("Please input the IP address of the server \n", argv[0]); exit(1); } //设置一个socket地址结构client_addr,代表客户机internet地址, 端口 struct sockaddr_in client_addr; bzero(&client_addr, sizeof(client_addr)); //把一段内存区的内容全部设置为0 client_addr.sin_family = AF_INET; //internet协议族 client_addr.sin_addr.s_addr = htons(INADDR_ANY); //INADDR_ANY表示自动获取本机地址 client_addr.sin_port = htons(0); //0表示让系统自动分配一个空闲端口 //创建用于internet的流协议(TCP)socket,用client_socket代表客户机socket int client_socket = socket(AF_INET, SOCK_STREAM, 0); if (client_socket < 0) { printf("Create Socket Failed!\n"); exit(1); } //把客户机的socket和客户机的socket地址结构联系起来 if (bind(client_socket, (struct sockaddr*) &client_addr, sizeof(client_addr))) { printf("Client Bind Port Failed!\n"); exit(1); } //设置一个socket地址结构server_addr,代表服务器的internet地址, 端口 struct sockaddr_in server_addr; bzero(&server_addr, sizeof(server_addr)); server_addr.sin_family = AF_INET; if (inet_aton(argv[1], &server_addr.sin_addr) == 0) //服务器的IP地址来自程序的参数 { printf("Server IP Address Error! \n"); exit(1); } server_addr.sin_port = htons(SERVER_PORT); socklen_t server_addr_length = sizeof(server_addr); // 向服务器发起连接,连接成功后client_socket代表了客户机和服务器的一个socket连接 if (connect(client_socket, (struct sockaddr*) &server_addr, server_addr_length) < 0) { printf("Can Not Connect To %s!\n", argv[1]); exit(1); } // 连接上服务器, 选择要上传的文件 char file_name[FILE_NAME_MAX_SIZE + 1];bzero (file_name, FILE_NAME_MAX_SIZE + 1); printf("Please Input File Name Upload To Server: "); scanf("%s", file_name); char buffer[BUFFER_SIZE]; bzero(buffer, BUFFER_SIZE); strncpy(buffer, file_name, strlen(file_name) > BUFFER_SIZE? BUFFER_SIZE : strlen(file_name)); FILE * fp = fopen(file_name, "r"); if (NULL == fp) { printf("File: %s NOT FOUND! \n", file_name); exit(1); } // 发送文件名 int nameLength = send(client_socket, buffer, BUFFER_SIZE, 0); if (nameLength < 0) { printf("File name Error! \n"); exit(0); } bzero(buffer, BUFFER_SIZE); int file_block_length = 0; while ((file_block_length = fread(buffer, sizeof(char), BUFFER_SIZE, fp)) > 0) { if (send(client_socket, buffer, file_block_length, 0) < 0) { printf("Send File:\t%s Failed\n", file_name); break; } bzero(buffer, BUFFER_SIZE); } printf("File:\t%s Transfer Finished\n", file_name); fclose(fp); close(client_socket); return 0; }