linux下socket通信程序例子

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server.c

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====================================================================

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#include<netinet/in.h>//forsockaddr_in

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#include<sys/types.h>//forsocket

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#include<sys/socket.h>//forsocket

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#include<stdio.h>//forprintf

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#include<stdlib.h>//forexit

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#include<string.h>//forbzero

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/*

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#include<sys/types.h>

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#include<sys/stat.h>

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#include<fcntl.h>

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#include<unistd.h>

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*/

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#defineHELLO_WORLD_SERVER_PORT6666

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#defineLENGTH_OF_LISTEN_QUEUE20

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#defineBUFFER_SIZE1024

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#defineFILE_NAME_MAX_SIZE512

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int

main(

int

argc,

char

**argv)

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{

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//设置一个socket地址结构server_addr,代表服务器internet地址,端口

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struct

sockaddr_inserver_addr;

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bzero(&server_addr,

sizeof

(server_addr));

//把一段内存区的内容全部设置为0

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server_addr.sin_family=AF_INET;

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server_addr.sin_addr.s_addr=htons(INADDR_ANY);

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server_addr.sin_port=htons(HELLO_WORLD_SERVER_PORT);

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//创建用于internet的流协议(TCP)socket,用server_socket代表服务器socket

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int

server_socket=socket(PF_INET,SOCK_STREAM,0);

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if

(server_socket<0)

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{

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printf

(

"CreateSocketFailed!"

);

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exit

(1);

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}

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{

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int

opt=1;

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setsockopt(server_socket,SOL_SOCKET,SO_REUSEADDR,&opt,

sizeof

(opt));

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}

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//把socket和socket地址结构联系起来

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if

(bind(server_socket,(

struct

sockaddr*)&server_addr,

sizeof

(server_addr)))

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{

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printf

(

"ServerBindPort:%dFailed!"

,HELLO_WORLD_SERVER_PORT);

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exit

(1);

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}

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//server_socket用于监听

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if

(listen(server_socket,LENGTH_OF_LISTEN_QUEUE))

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{

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printf

(

"ServerListenFailed!"

);

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exit

(1);

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}

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while

(1)

//服务器端要一直运行

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{

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//定义客户端的socket地址结构client_addr

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struct

sockaddr_inclient_addr;

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socklen_tlength=

sizeof

(client_addr);

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//接受一个到server_socket代表的socket的一个连接

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//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

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//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

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//new_server_socket代表了服务器和客户端之间的一个通信通道

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//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

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int

new_server_socket=accept(server_socket,(

struct

sockaddr*)&client_addr,&length);

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if

(new_server_socket<0)

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{

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printf

(

"ServerAcceptFailed!\n"

);

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break

;

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}

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char

buffer[BUFFER_SIZE];

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bzero(buffer,BUFFER_SIZE);

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length=recv(new_server_socket,buffer,BUFFER_SIZE,0);

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if

(length<0)

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{

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printf

(

"ServerRecieveDataFailed!\n"

);

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break

;

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}

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char

file_name[FILE_NAME_MAX_SIZE+1];

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bzero(file_name,FILE_NAME_MAX_SIZE+1);

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strncpy

(file_name,buffer,

strlen

(buffer)>FILE_NAME_MAX_SIZE?FILE_NAME_MAX_SIZE:

strlen

(buffer));

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//intfp=open(file_name,O_RDONLY);

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//if(fp<0)

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printf

(

"%s\n"

,file_name);

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FILE

*fp=

fopen

(file_name,

"r"

);

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if

(NULL==fp)

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{

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printf

(

"File:\t%sNotFound\n"

,file_name);

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}

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else

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{

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bzero(buffer,BUFFER_SIZE);

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int

file_block_length=0;

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//while((file_block_length=read(fp,buffer,BUFFER_SIZE))>0)

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while

((file_block_length=

fread

(buffer,

sizeof

(

char

),BUFFER_SIZE,fp))>0)

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{

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printf

(

"file_block_length=%d\n"

,file_block_length);

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//发送buffer中的字符串到new_server_socket,实际是给客户端

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if

(send(new_server_socket,buffer,file_block_length,0)<0)

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{

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printf

(

"SendFile:\t%sFailed\n"

,file_name);

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break

;

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}

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bzero(buffer,BUFFER_SIZE);

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}

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//close(fp);

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fclose

(fp);

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printf

(

"File:\t%sTransferFinished\n"

,file_name);

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}

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//关闭与客户端的连接

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close(new_server_socket);

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}

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//关闭监听用的socket

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close(server_socket);

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return

0;

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}