server和client简单例子

1.代码c代码 server部分跳至123全屏预览?123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119server.c=#include / for sockaddr_in#include / for socket#include / for socket#include / for printf#include / for exit#include / for bzero/*#include #include #include #include */#define HELLO_WORLD_SERVER_PORT 6666 #define LENGTH_OF_LISTEN_QUEUE 20#define BUFFER_SIZE 1024#define FILE_NAME_MAX_SIZE 512int main(int argc, char *argv)/设置一个socket地址结构server_addr,代表服务器internet地址, 端口struct sockaddr_in server_addr;bzero(&server_addr,sizeof(server_addr); /把一段内存区的内容全部设置为0server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = htons(INADDR_ANY);server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);/创建用于internet的流协议(TCP)socket,用server_socket代表服务器socketint server_socket = socket(PF_INET,SOCK_STREAM,0);if( server_socket 0)printf(Create Socket Failed!);exit(1); int opt =1;setsockopt(server_socket,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt);/把socket和socket地址结构联系起来if( bind(server_socket,(struct sockaddr*)&server_addr,sizeof(server_addr)printf(Server Bind Port : %d Failed!, HELLO_WORLD_SERVER_PORT); exit(1);/server_socket用于监听if ( listen(server_socket, LENGTH_OF_LISTEN_QUEUE) )printf(Server Listen Failed!); exit(1);while (1) /服务器端要一直运行/定义客户端的socket地址结构client_addrstruct sockaddr_in client_addr;socklen_t length = sizeof(client_addr);/接受一个到server_socket代表的socket的一个连接/如果没有连接请求,就等待到有连接请求-这是accept函数的特性/accept函数返回一个新的socket,这个socket(new_server_socket)用于同连接到的客户的通信/new_server_socket代表了服务器和客户端之间的一个通信通道/accept函数把连接到的客户端信息填写到客户端的socket地址结构client_addr中int new_server_socket = accept(server_socket,(struct sockaddr*)&client_addr,&length);if ( new_server_socket 0)printf(Server Accept Failed!n);break;char bufferBUFFER_SIZE;bzero(buffer, BUFFER_SIZE);length = recv(new_server_socket,buffer,BUFFER_SIZE,0);if (length FILE_NAME_MAX_SIZE?FILE_NAME_MAX_SIZE:strlen(buffer);/ int fp = open(file_name, O_RDONLY);/ if( fp 0)while( (file_block_length = fread(buffer,sizeof(char),BUFFER_SIZE,fp)0)printf(file_block_length = %dn,file_block_length);/发送buffer中的字符串到new_server_socket,实际是给客户端if(send(new_server_socket,buffer,file_block_length,0)0)printf(Send File:t%s Failedn, file_name);break;bzero(buffer, BUFFER_SIZE);/ close(fp);fclose(fp);printf(File:t%s Transfer Finishedn,file_name);/关闭与客户端的连接close(new_server_socket);/关闭监听用的socketclose(server_socket);return 0;2.代码c代码 client部分?123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111client.c#include / for sockaddr_in#include / for socket#include / for socket#include / for printf#include / for exit#include / for bzero/*#include #include #include #include */#define HELLO_WORLD_SERVER_PORT 6666 #define BUFFER_SIZE 1024#define FILE_NAME_MAX_SIZE 512int main(int argc, char *argv)if (argc != 2)printf(Usage: ./%s ServerIPAddressn,argv0);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0client_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socketint 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(argv1,&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(HELLO_WORLD_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) BUFFER_SIZE?BUFFER_SIZE:strlen(file_name);/向服务器发送buffer中的数据send(client_socket,buffer,BUFFER_SIZE,0);/ int fp = open(file_name, O_WRONLY|O_CREAT);/ if( fp 0 )FILE * fp = fopen(file_name,w);if(NULL = fp )printf(File:t%s Can Not Open To Writen, file_name);exit(1);/从服务器接收数据到buffer中bzero(buffer,BUFFER_SIZE);int length = 0;while( length = recv(client_socket,buffer,BUFFER_SIZE,0)if(length 0)printf(Recieve Data From Server %s Failed!n, argv1);break;/ int write_length = write(fp, buffer,length);int write_length = fwrite(buffer,sizeof(char),length,fp);if (write_lengthlength)printf(File:t%s Write Failedn, file_name);break;bzero(buffer,BUFFER_SIZE); printf(Recieve File:t %s From Server%s Finishedn,file_name, argv1);close(fp);/关闭socketclose(client_socket);return 0;3.代码open等，fopen等说明?123456789101112131415161718192021222324252627282930某些注释部分，open,read,write被 fopen,fread,fwrite替换。说明一下：fopen, fclose, fread, fwrite, fgetc, fgets, fputc, fputs, freopen, fseek, ftell, rewind等缓冲文件系统缓冲文件系统的特点是：在内存开辟一个“缓冲区”，为程序中的每一个文件使用，当执行读文件的操作时，从磁盘文件将数据先读入内存“缓冲区”， 装满后再从内存“缓冲区”依此读入接收的变量。执行写文件的操作时，先将数据写入内存“缓冲区”，待内存“缓冲区”装满后再写入文件。由此可以看出，内存 “缓冲区”的大小，影响着实际操作外存的次数，内存“缓冲区”越大，则操作外存的次数就少，执行速度就快、效率高。一般来说，文件“缓冲区”的大小随机器 而定。open, close, read, write, getc, getchar, putc, putchar 等非缓冲文件系统非缓冲文件系统是借助文件结构体指针来对文件进行管理，通过文件指针来对文件进行访问，既可以读写字符、字符串、格式化数据，也可以读写二进制数 据。非缓