put filename：客户端输入put 文件名---》把put 文件名发送给服务器---》接收put 文件名---》判断是否为put -----》（cp：源文件再客户端所在路径下，目标文件在服务器所在路径下）客户端循环读源文件发送给服务器，服务器循环接收写到目标文件里--------》发送一个结束“end”的标志

接收大小与发送大小一致（避免沾包）

客户端：

#include <stdio.h>
#include <arpa/inet.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
void show()
{printf("***************list**************\n");printf("***********put filename**********\n");printf("***********get filename**********\n");printf("**************quit***************\n");
}
int list(int acceptfd)
{char buf[128];int ret;while (1){ret = recv(acceptfd, buf, sizeof(buf), 0);if (ret < 0){printf("recv err\n");return -1;}else if (ret == 0){printf("client exit\n");return -1;}if (!strcmp(buf, "end")){printf("\n");break;}printf("%s ", buf);}
}
int put(int sockfd, char *p)
{char buf[128];int fd = open(p + 4, O_RDONLY);if (fd < 0){printf("open err\n");return -1;}while (read(fd, buf, sizeof(buf)-1)){send(sockfd, buf, sizeof(buf), 0);memset(buf, 0, sizeof(buf));}strcpy(buf, "over");send(sockfd, buf, sizeof(buf), 0);close(fd);
}
int get(int sockfd, char *p)
{char buf[128]={0};int fd = open(p + 4, O_WRONLY | O_CREAT | O_TRUNC ,0777);if (fd < 0){printf("get open err\n");return -1;}while (1){int ret = recv(sockfd, buf, sizeof(buf), 0);if (ret < 0){perror("recv err");return -1;}else if (ret == 0){printf("client exit\n");break;}if (!strcmp(buf, "over"))break;write(fd, buf, strlen(buf));memset(buf, 0, sizeof(buf));}close(fd);
}
int main(int argc, char const *argv[])
{char buf[128] = {0};// 1.创建套接字（socket）------------》有手机int sockfd = socket(AF_INET, SOCK_STREAM, 0);if (sockfd < 0){perror("socket err");return -1;}printf("sockfd:%d\n", sockfd);// 2.指定（服务器）网络信息--------》有对方的号码struct sockaddr_in saddr;saddr.sin_family = AF_INET;saddr.sin_port = htons(atoi(argv[1]));saddr.sin_addr.s_addr = inet_addr("192.168.50.241"); //saddr.sin_addr.s_addr = INADDR_ANY;// 3.连接（connect）-------------------》拨打电话if (connect(sockfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0){perror("connect err");return -1;}printf("connect okk\n");// 4.接收发送消息（recv send）---》通话show();while (1){fgets(buf, sizeof(buf), stdin);if (buf[strlen(buf) - 1] == '\n')buf[strlen(buf) - 1] = '\0';send(sockfd, buf, sizeof(buf), 0);if (!strcmp(buf, "quit"))break;else if (!strcmp(buf, "list"))list(sockfd);else if (!strncmp(buf, "put ", 4))put(sockfd, buf);else if (!strncmp(buf, "get ", 4))get(sockfd, buf);elseprintf("命令无效，请重新输入\n");memset(buf,0, sizeof(buf));// write(sockfd, buf, sizeof(buf));}// 5.关闭套接字（close）------------》挂电话close(sockfd);return 0;
}

服务器：

#include <stdio.h>
#include <arpa/inet.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
int list(int acceptfd)
{char buf[128];DIR *dr = opendir(".");if (dr == NULL){printf("opendir err\n");return -1;}struct dirent *dir;while (dir = readdir(dr)){struct stat dir1;stat(dir->d_name, &dir1);if ((dir1.st_mode & __S_IFMT) == __S_IFREG){strcpy(buf, dir->d_name);send(acceptfd, buf, sizeof(buf), 0);memset(buf, 0, sizeof(buf));}}strcpy(buf, "end");send(acceptfd, buf, sizeof(buf), 0);closedir(dr);
}
int get(int acceptfd, char *p)
{char buf[128];int fd = open(p + 4, O_RDONLY);if (fd < 0){printf("open err\n");return -1;}while (read(fd, buf, sizeof(buf))){send(acceptfd, buf, sizeof(buf), 0);memset(buf, 0, sizeof(buf));}strcpy(buf, "over");send(acceptfd, buf, sizeof(buf), 0);close(fd);
}
int put(int acceptfd, char *p)
{char buf[128] = {0};int fd = open(p + 4, O_WRONLY | O_CREAT | O_TRUNC, 0777);if (fd < 0){printf("get open err\n");return -1;}while (1){int ret = recv(acceptfd, buf, sizeof(buf), 0);if (ret < 0){perror("recv err");return -1;}else if (ret == 0){printf("client exit\n");break;}if (!strcmp(buf, "over"))break;write(fd, buf, strlen(buf));memset(buf, 0, sizeof(buf));}close(fd);
}
int main(int argc, char const *argv[])
{char buf[128] = {0};int ret, acceptfd;// 1.创建套接字（socket）---------------》有手机int sockfd = socket(AF_INET, SOCK_STREAM, 0);if (sockfd < 0){perror("socket err");return -1;}printf("sockfd:%d\n", sockfd); // 3// 2.指定网络信息---------------------------》有号码struct sockaddr_in saddr, caddr;saddr.sin_family = AF_INET;            // IPV4saddr.sin_port = htons(atoi(argv[1])); // 端口号saddr.sin_addr.s_addr = inet_addr("192.168.50.241"); // 虚拟机IP// saddr.sin_addr.s_addr = inet_addr("0.0.0.0");//saddr.sin_addr.s_addr = INADDR_ANY;int len = sizeof(caddr);// 3.绑定套接字（bind）------------------》绑定手机（插卡）if (bind(sockfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0){perror("bind err");return -1;}printf("bind ok\n");// 4.监听套接字（listen）-----------------》待机if (listen(sockfd, 6) < 0){perror("listen err");return -1;}printf("listen ok\n");// 5.接收客户端连接连接请求（accept）--》接电话// tcp服务器一共有两类文件描述符,一类用于连接,一类用于通信// socket函数返回值:用于连接的文件描述符// accept函数返回值:用于通信的文件描述符while (1){acceptfd = accept(sockfd, (struct sockaddr *)&caddr, &len);if (acceptfd < 0){perror("accept err");return -1;}printf("port:%d ip:%s\n", ntohs(caddr.sin_port), inet_ntoa(caddr.sin_addr));printf("acceptfd:%d\n", acceptfd);// 6.接收、发送数据（recv send）---》通话while (1){// read/write()ret = recv(acceptfd, buf, sizeof(buf), 0);if (ret < 0){perror("recv err");return -1;}else if (ret == 0){printf("client exit\n");break;}if (!strcmp(buf, "list"))list(acceptfd);else if (!strncmp(buf, "get ", 4))put(acceptfd, buf);else if (!strncmp(buf, "put ", 4))put(acceptfd, buf);}close(acceptfd);}close(sockfd);return 0;
}