C/C++编程：实现跨平台传输文件（TCP版）

逃离我推掉我的手 2022-11-07 11:48 185阅读 0赞

# 第一个版本 #

//makefile-win

.SUFFIXES: .c .o
    CC=gcc
    SERVERSRCS=server.c\
                pub.c
    CLIENTSRCS=client.c\
                pub.c
            
    SERVEROBJS=$(SERVERSRCS:.c=.o)
    CLIENTOBJS=$(CLIENTSRCS:.c=.o)
    SERVEREXEC=server.exe
    CLIENTEXEC=client.exe
    all:$(SERVEROBJS) $(CLIENTOBJS)
        $(CC) -static -o $(SERVEREXEC) $(SERVEROBJS) -lWs2_32
        $(CC) -static -o $(CLIENTEXEC) $(CLIENTOBJS) -lWs2_32 
        @echo '-------------ok--------------'
    .c.o:
        $(CC) -Wall -DWIN -o $@ -c $< 
    clean:
        rm -f $(SERVEROBJS)
        rm -f $(CLIENTOBJS)
        rm -f core*

//makefile

.SUFFIXES: .c .o
    CC=gcc
    SERVERSRCS=server.c\
                pub.c
    CLIENTSRCS=client.c\
                pub.c
            
    SERVEROBJS=$(SERVERSRCS:.c=.o)
    CLIENTOBJS=$(CLIENTSRCS:.c=.o)
    SERVEREXEC=server
    CLIENTEXEC=client
    all:$(SERVEROBJS) $(CLIENTOBJS)
        $(CC) -o $(SERVEREXEC) $(SERVEROBJS)
        $(CC) -o $(CLIENTEXEC) $(CLIENTOBJS)
        @echo '-------------ok--------------'
    .c.o:
        $(CC) -Wall -o $@ -c $< 
    clean:
        rm -f $(SERVEROBJS)
        rm -f $(CLIENTOBJS)
        rm -f core*

//pub.h

#ifndef PUB_H_
    #define PUB_H_
    int send_work(const char *hostname, int port, const char *filename);
    int recv_work(int port);
    #endif /* PUB_H_ */

// //pub.c

#ifdef WIN
    #include <WinSock2.h>
    #else
    #include <stdlib.h>
    #include <unistd.h>
    #include <sys/socket.h>
    #include <arpa/inet.h>
    #include <errno.h>
    #include <string.h>
    #define SOCKET int
    #endif
     
    #include <stdio.h>
    #include "pub.h"
     
    #define BUFSIZE 262144  //256k
     
    void getfilename(const char *filename, char *name)//从完整路径名中解析出文件名称，例如：/home/test/abc.txt,解析完成后为abc.txt
    {
        
    	int len = strlen(filename);
    	int i;
    	for (i = (len - 1); i >= 0; i--)
    	{
        
    		if ((filename[i] == '\\') || (filename[i] == '/'))
    		{
        
    			break;
    		}
    	}
    	strcpy(name, &filename[i + 1]);
    	return;
    }
     
    SOCKET init_socket()//初始化socket
    {
        
    //如果是windows，执行如下代码
    #ifdef WIN
    	WORD wVersionRequested;
    	WSADATA wsaData;
    	int err;
    	wVersionRequested = MAKEWORD(1, 1);
    	err = WSAStartup(wVersionRequested, &wsaData);
    	if (err != 0)
    	{
        
    		return -1;
    	}
     
    	if (LOBYTE(wsaData.wVersion) != 1 || HIBYTE(wsaData.wVersion) != 1)
    	{
        
    		WSACleanup();
    		return -1;
    	}
    #endif
     
    	return 0;
    }
     
    SOCKET socket_connect(const char *hostname, int port)//连接到指定的主机和端口号
    {
        
    	if (init_socket() == -1)
    		return 0;
     
    	SOCKET st = socket(AF_INET, SOCK_STREAM, 0);//建立TCP socket
    	if (st == 0)
    		return 0;
    	struct sockaddr_in addr;
    	memset(&addr, 0, sizeof(addr));
    	addr.sin_family = AF_INET;
    	addr.sin_port = htons(port);//指定port为要连接的端口号
    	addr.sin_addr.s_addr = inet_addr(hostname);//指定hostname为要连接的IP地址
    	if (connect(st, (struct sockaddr *) &addr, sizeof(addr)) == -1)
    	{
        
    		printf("connect to %s:%d failed %s\n", hostname, port, strerror(errno));
    		return 0;//连接失败，返回0
    	} else
    	{
        
    		return st;//连接成功，返回socket描述符
    	}
    }
     
    SOCKET socket_create(int port)//在port指定的端口上建立server端socket
    {
        
    	if (init_socket() == -1)
    		return 0;
     
    	SOCKET st = socket(AF_INET, SOCK_STREAM, 0);//建立TCP socket
    	if (st == 0)
    		return 0;//如果建立socket失败，返回0
     
    #ifdef WIN
    	const char on = 0;
    #else
    	int on = 0;
    #endif
     
    	if (setsockopt(st, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
    	{
        
    		printf("setsockopt failed %s\n", strerror(errno));
    		return 0;
    	}
    	struct sockaddr_in addr;
    	memset(&addr, 0, sizeof(addr));
    	addr.sin_family = AF_INET;
    	addr.sin_port = htons(port);
    	addr.sin_addr.s_addr = htonl(INADDR_ANY);
    	if (bind(st, (struct sockaddr *) &addr, sizeof(addr)) == -1)//server端socket，所以需要绑定IP地址
    	{
        
    		printf("bind failed %s\n", strerror(errno));
    		return 0;
    	}
    	if (listen(st, 20) == -1)
    	{
        
    		printf("listen failed %s\n", strerror(errno));
    		return 0;
    	}
    	printf("listen %d success\n", port);
    	return st;//server端socket建立成功,返回server端socket描述符
    }
     
    SOCKET socket_accept(SOCKET listen_st)//server端socket开始accept的函数
    {
        
    	struct sockaddr_in client_addr;
     
    #ifdef WIN
    	int len = 0;
    #else
    	unsigned int len = 1;
    #endif
     
    	len = sizeof(client_addr);
    	memset(&client_addr, 0, sizeof(client_addr));
    	SOCKET client_st = accept(listen_st, (struct sockaddr *) &client_addr,
    			&len);//accept阻塞，直到有client连接到server才返回
    	if (client_st == -1)
    	{
        
    		printf("accept failed %s\n", strerror(errno));
    		return 0;
    	} else
    	{
        
    		printf("accept by %s\n", inet_ntoa(client_addr.sin_addr));
    		return client_st;//有client连接到server，返回client的socket描述符
    	}
    }
     
    int send_work(const char *hostname, int port, const char *filename)//向hostname指定的IP地址发送filename指定的文件
    {
        
    	SOCKET st = socket_connect(hostname, port);//连接到hostname指定的IP地址和port指定的端口号
    	if (st == 0)//连接失败，函数返回
    		return 0;
     
    	FILE *fd = fopen(filename, "rb");//以只读方式打开filename指定的文件
    	if (fd == NULL)//如果文件打开失败，函数返回
    	{
        
    		printf("open %s failed %s\n", filename, strerror(errno));
    		return 0;
    	}
     
    	char *buf = malloc(BUFSIZE);//申请一个缓冲区，存放接收到的文件内容
    	memset(buf, 0, BUFSIZE);
    	getfilename(filename, buf);//从完整路径名中解析出文件名称，例如：/home/test/abc.txt,解析完成后为abc.txt
    	size_t rc = send(st, buf, strlen(buf), 0);//客户端第一次给server端发送的数据为要传递的文件名称，将解析完成后的文件名通过socket发送给server端
    	if (rc <= 0)
    	{
        
    		if (rc < 0)
    			printf("send failed %s\n", strerror(errno));
    		else
    			printf("socket disconnect\n");
     
    	} else
    	{
        
     
    		memset(buf, 0, BUFSIZE);
    		if (recv(st, buf, BUFSIZE, 0) <= 0)//接收来自server端的回复
    		{
        
    			if (rc < 0)
    				printf("recv failed %s\n", strerror(errno));
    			else
    				printf("socket disconnect\n");
    		} else
    		{
        
    			if (strncmp(buf, "OK", 2) == 0)//如果收到来自服务端的回复，代表服务端认可，可以发送文件了
    			{
        
    				while (1)
    				{
        
    					memset(buf, 0, BUFSIZE);
    					rc = fread(buf, 1, BUFSIZE, fd);//循环读取文件，直到读到文件尾，循环break
    					if (rc <= 0)
    					{
        
    						if (rc < 0)
    							printf("fread failed %s\n", strerror(errno));
    						break;
    					} else
    					{
        
    						rc = send(st, buf, rc, 0);//将从文件中读到的数据，通过socket发送到server端，其中rc为从文件中读到的数据大小
    						if (rc <= 0)//如果发送失败，代表TCP连接出错，循环break
    						{
        
    							if (rc < 0)
    								printf("send failed %s\n", strerror(errno));
    							else
    								printf("socket disconnect\n");
    							break;
    						}
    					}
    				}
    			}
    		}
    	}
     
    	fclose(fd);
    	free(buf);
     
    #ifdef WIN	
    	closesocket(st);
    	WSACleanup();
    #else	
    	close(st);
    #endif
    	return 1;
    }
     
    int recv_work(int port)//server端socket在port指定的端口上listen，接收来自client发送的文件
    {
        
    	SOCKET listen_st = socket_create(port);//建立server端socket，在port指定端口listen
    	if (listen_st == 0)//如果创建服务端socket失败，函数返回0
    		return 0;
    	SOCKET st = socket_accept(listen_st);//如果有client连接到达，socket_accept函数返回client的socket描述符
    	if (st == 0)
    		return 0;
     
    	char *buf = malloc(BUFSIZE);//建立接收文件数据缓冲区
    	FILE *fd = NULL;
     
    	memset(buf, 0, BUFSIZE);
    	size_t rc = recv(st, buf, BUFSIZE, 0);//接收来自client的数据，客户端第一次要发送的文件名称
    	if (rc <= 0)
    	{
        
    		if (rc < 0)
    			printf("recv failed %s\n", strerror(errno));
    		else
    			printf("socket disconnect\n");
     
    	} else
    	{
        
    		printf("receiving %s\n", buf);
     
    		fd = fopen(buf, "wb");//以只写方式打开文件
    		if (fd == NULL)
    		{
        
    			printf("open %s failed %s\n", buf, strerror(errno));
    		} else
    		{
        
    			memset(buf, 0, BUFSIZE);
    			strcpy(buf, "OK");
    			rc = send(st, buf, strlen(buf), 0);//回复客户端，同意接收文件
    			if (rc <= 0)
    			{
        
    				if (rc < 0)
    					printf("send failed %s\n", strerror(errno));
    				else
    					printf("socket disconnect\n");
    			}
     
    			while (1)
    			{
        
    				memset(buf, 0, BUFSIZE);
    				rc = recv(st, buf, BUFSIZE, 0);//循环接收来自client的数据，数据为发送文件的内容
    				if (rc <= 0)//如果client连接断开，代表文件传递完成，或者网络意外中断,循环break
    				{
        
    					if (rc < 0)
    						printf("recv failed %s\n", strerror(errno));
    					else
    						printf("socket disconnect\n");
    					break;
    				} else
    				{
        
    					fwrite(buf, 1, rc, fd);//将从client端收到的内容写入文件
    				}
    			}
    		}
    	}
     
    	if (fd)
    		fclose(fd);//关闭打开的文件
    	free(buf);
     
    #ifdef WIN	
    	closesocket(st);
    	closesocket(listen_st);
    	WSACleanup();
    #else	
    	close(st);
    	close(listen_st);
    #endif
    	return 1;
    }

//client.c

#include <stdio.h>
    #include <stdlib.h>
    #include "pub.h"
     
    int main(int arg, char *args[])
    {
        
    	if (arg < 4)//如果参数小于3个，main函数退出
    	{
        
    		printf("usage:client host port filename\n");
    		return EXIT_FAILURE;
    	}
     
    	int iport = atoi(args[2]);//将第二个参数转化为端口号
    	if (iport == 0)//如果端口号为0，main函数退出
    	{
        
    		printf("port %d is invalid\n", iport);
    		return EXIT_FAILURE;
    	}
     
    	printf("%s send begin\n", args[3]);
    	if (send_work(args[1], iport, args[3]) == 1)//将第一个参数做为IP地址，第二个参数做为端口号，第三个参数做为要发送的文件名传递给send_work函数
    		printf("%s send success\n", args[3]);
    	else
    		printf("%s send fail\n", args[3]);
     
    	return EXIT_SUCCESS;
    }

//server.c

#include <stdio.h>
    #include <stdlib.h>
    #include "pub.h"
     
    int main(int arg, char *args[])
    {
        
    	if (arg < 2)//如果没有参数，main函数退出
    	{
        
    		printf("usage:server port\n");
    		return EXIT_FAILURE;
    	}
     
    	int iport = atoi(args[1]);//将第一个参数转化为端口号，server端socket要在这个端口号上listen
    	if (iport == 0)
    	{
        
    		printf("port %d is invalid\n", iport);
    		return EXIT_FAILURE;
    	}
     
    	printf("recv is begin\n");
    	if (recv_work(iport) == 1)//server端socket在port指定的端口上listen，接收来自client发送的文件
    		printf("recv success\n");
    	else
    		printf("recv fail\n");
    	return EXIT_SUCCESS;
    }

# 第二个版本：修改为可以处理多个连接的并发服务器 #

pub.cpp

#ifdef WIN
    #include <WinSock2.h>
    #else
    #include <stdlib.h>
    #include <unistd.h>
    #include <sys/socket.h>
    #include <arpa/inet.h>
    #include <errno.h>
    #include <string.h>
    #define SOCKET int
    #endif
    
    #include <stdio.h>
    #include "pub.h"
    
    #define BUFSIZE 262144  //256k
    
    void getfilename(const char *filename, char *name)//从完整路径名中解析出文件名称，例如：/home/test/abc.txt,解析完成后为abc.txt
    {
        
        int len = strlen(filename);
        int i;
        for (i = (len - 1); i >= 0; i--)
        {
        
            if ((filename[i] == '\\') || (filename[i] == '/'))
            {
        
                break;
            }
        }
        strcpy(name, &filename[i + 1]);
        return;
    }
    
    SOCKET init_socket()//初始化socket
    {
        
    //如果是windows，执行如下代码
    #ifdef WIN
        WORD wVersionRequested;
    	WSADATA wsaData;
    	int err;
    	wVersionRequested = MAKEWORD(1, 1);
    	err = WSAStartup(wVersionRequested, &wsaData);
    	if (err != 0)
    	{
        
    		return -1;
    	}
     
    	if (LOBYTE(wsaData.wVersion) != 1 || HIBYTE(wsaData.wVersion) != 1)
    	{
        
    		WSACleanup();
    		return -1;
    	}
    #endif
    
        return 0;
    }
    
    SOCKET socket_connect(const char *hostname, int port)//连接到指定的主机和端口号
    {
        
        if (init_socket() == -1)
            return 0;
    
        SOCKET st = socket(AF_INET, SOCK_STREAM, 0);//建立TCP socket
        if (st == 0)
            return 0;
        struct sockaddr_in addr;
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);//指定port为要连接的端口号
        addr.sin_addr.s_addr = inet_addr(hostname);//指定hostname为要连接的IP地址
        if (connect(st, (struct sockaddr *) &addr, sizeof(addr)) == -1)
        {
        
            printf("connect to %s:%d failed %s\n", hostname, port, strerror(errno));
            return 0;//连接失败，返回0
        } else
        {
        
            return st;//连接成功，返回socket描述符
        }
    }
    
    SOCKET socket_create(int port)//在port指定的端口上建立server端socket
    {
        
        if (init_socket() == -1)
            return 0;
    
        SOCKET st = socket(AF_INET, SOCK_STREAM, 0);//建立TCP socket
        if (st == 0)
            return 0;//如果建立socket失败，返回0
    
    #ifdef WIN
        const char on = 0;
    #else
        int on = 0;
    #endif
    
        if (setsockopt(st, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
        {
        
            printf("setsockopt failed %s\n", strerror(errno));
            return 0;
        }
        struct sockaddr_in addr;
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = htonl(INADDR_ANY);
        if (bind(st, (struct sockaddr *) &addr, sizeof(addr)) == -1)//server端socket，所以需要绑定IP地址
        {
        
            printf("bind failed %s\n", strerror(errno));
            return 0;
        }
        if (listen(st, 20) == -1)
        {
        
            printf("listen failed %s\n", strerror(errno));
            return 0;
        }
        printf("listen %d success\n", port);
        return st;//server端socket建立成功,返回server端socket描述符
    }
    
    SOCKET socket_accept(SOCKET listen_st)//server端socket开始accept的函数
    {
        
        struct sockaddr_in client_addr;
    
    #ifdef WIN
        int len = 0;
    #else
        unsigned int len = 1;
    #endif
    
        len = sizeof(client_addr);
        memset(&client_addr, 0, sizeof(client_addr));
        SOCKET client_st = accept(listen_st, (struct sockaddr *) &client_addr,
                                  &len);//accept阻塞，直到有client连接到server才返回
        if (client_st == -1)
        {
        
            printf("accept failed %s\n", strerror(errno));
            return 0;
        } else
        {
        
            printf("accept by %s\n", inet_ntoa(client_addr.sin_addr));
            return client_st;//有client连接到server，返回client的socket描述符
        }
    }
    
    int send_work(const char *hostname, int port, const char *filename)//向hostname指定的IP地址发送filename指定的文件
    {
        
        SOCKET st = socket_connect(hostname, port);//连接到hostname指定的IP地址和port指定的端口号
        if (st == 0)//连接失败，函数返回
            return 0;
    
        FILE *fd = fopen(filename, "rb");//以只读方式打开filename指定的文件
        if (fd == NULL)//如果文件打开失败，函数返回
        {
        
            printf("open %s failed %s\n", filename, strerror(errno));
            return 0;
        }
    
        char *buf = (char *)malloc(BUFSIZE);//申请一个缓冲区，存放接收到的文件内容
        memset(buf, 0, BUFSIZE);
        getfilename(filename, buf);//从完整路径名中解析出文件名称，例如：/home/test/abc.txt,解析完成后为abc.txt
        size_t rc = send(st, buf, strlen(buf), 0);//客户端第一次给server端发送的数据为要传递的文件名称，将解析完成后的文件名通过socket发送给server端
        if (rc <= 0)
        {
        
            if (rc < 0)
                printf("send failed %s\n", strerror(errno));
            else
                printf("socket disconnect\n");
    
        } else
        {
        
    
            memset(buf, 0, BUFSIZE);
            if (recv(st, buf, BUFSIZE, 0) <= 0)//接收来自server端的回复
            {
        
                if (rc < 0)
                    printf("recv failed %s\n", strerror(errno));
                else
                    printf("socket disconnect\n");
            } else
            {
        
                if (strncmp(buf, "OK", 2) == 0)//如果收到来自服务端的回复，代表服务端认可，可以发送文件了
                {
        
                    while (1)
                    {
        
                        memset(buf, 0, BUFSIZE);
                        rc = fread(buf, 1, BUFSIZE, fd);//循环读取文件，直到读到文件尾，循环break
                        if (rc <= 0)
                        {
        
                            if (rc < 0)
                                printf("fread failed %s\n", strerror(errno));
                            break;
                        } else
                        {
        
                            rc = send(st, buf, rc, 0);//将从文件中读到的数据，通过socket发送到server端，其中rc为从文件中读到的数据大小
                            if (rc <= 0)//如果发送失败，代表TCP连接出错，循环break
                            {
        
                                if (rc < 0)
                                    printf("send failed %s\n", strerror(errno));
                                else
                                    printf("socket disconnect\n");
                                break;
                            }
                        }
                    }
                }
            }
        }
    
        fclose(fd);
        free(buf);
    
    #ifdef WIN
        closesocket(st);
    	WSACleanup();
    #else
        close(st);
    #endif
        return 1;
    }
    void recv(SOCKET st);
    int recv_work(int port)//server端socket在port指定的端口上listen，接收来自client发送的文件
    {
        
        SOCKET listen_st = socket_create(port);//建立server端socket，在port指定端口listen
        if (listen_st == 0)//如果创建服务端socket失败，函数返回0
            return 0;
    
    
        for(;;){
        
            SOCKET st = socket_accept(listen_st);//如果有client连接到达，socket_accept函数返回client的socket描述符
            if (st == 0)
                continue;
    
    #ifdef WIN
            recv(st);
    #else
            pid_t               childpid;
            if( (childpid = fork()) == 0){
        
                close(listen_st);
                recv(st);
                exit(0);
            }
            close(st);
    #endif
        }
    
    #ifdef WIN
    	closesocket(listen_st);
    	WSACleanup();
    #else
        close(listen_st);
    #endif
        return 1;
    }
    
    
    void recv(SOCKET st){
        
        char *buf = (char *)malloc(BUFSIZE);//建立接收文件数据缓冲区
        FILE *fd = NULL;
    
        memset(buf, 0, BUFSIZE);
        size_t rc = recv(st, buf, BUFSIZE, 0);//接收来自client的数据，客户端第一次要发送的文件名称
        if (rc <= 0){
        
            if (rc < 0)
                printf("recv failed %s\n", strerror(errno));
            else
                printf("socket disconnect\n");
    
        } else{
        
            printf("receiving %s\n", buf);
    
            fd = fopen(buf, "wb");//以只写方式打开文件
            if (fd == NULL)
            {
        
                printf("open %s failed %s\n", buf, strerror(errno));
            } else{
        
                memset(buf, 0, BUFSIZE);
                strcpy(buf, "OK");
                rc = send(st, buf, strlen(buf), 0);//回复客户端，同意接收文件
                if (rc <= 0){
        
                    if (rc < 0)
                        printf("send failed %s\n", strerror(errno));
                    else
                        printf("socket disconnect\n");
                }
    
                while (1)
                {
        
                    memset(buf, 0, BUFSIZE);
                    rc = recv(st, buf, BUFSIZE, 0);//循环接收来自client的数据，数据为发送文件的内容
                    if (rc <= 0)//如果client连接断开，代表文件传递完成，或者网络意外中断,循环break
                    {
        
                        if (rc < 0)
                            printf("recv failed %s\n", strerror(errno));
                        else
                            printf("socket disconnect\n");
                        break;
                    } else
                    {
        
                        fwrite(buf, 1, rc, fd);//将从client端收到的内容写入文件
                    }
                }
            }
        }
    
        if (fd)
            fclose(fd);//关闭打开的文件
        free(buf);
    
    #ifdef WIN
        closesocket(st);
    #else
        close(st);
    #endif
    }