tcp客户端示例

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

typedef struct _NSS_HEADER

{

unsigned short ProtocolVersion; /* 协议版本信息 */

unsigned short MsgType; /* 消息类型 */

unsigned short TransactionNo; /* 传输编号 */

unsigned short PacketLength; /* 数据包长度,包括Header */

}NSS_HEADER;

int str_echo(int sockfd, unsigned short no)

{

ssize_t readLen;

ssize_t writeLen;

char buf[8];

NSS_HEADER *hdr = (NSS_HEADER*)buf;

memset( hdr, 0, sizeof(NSS_HEADER) );

hdr->TransactionNo = no;

// 写数据

int nWriteLen = 0;

while ( true )

{

writeLen = write(sockfd, &buf[nWriteLen], sizeof(NSS_HEADER)-nWriteLen);

// printf( "write %d/n", writeLen);

if (writeLen < 0 && errno == EINTR)

{

continue;

}

else if ( writeLen < 0 )

{

perror ( "write:" );

return -1;

}

nWriteLen += writeLen;

// 已写完，直接返回

if (nWriteLen >= sizeof(NSS_HEADER) )

{

break;

}

}

printf( "send data successed. trans no: %d/n", no );

// 读数据

int nReadLen = 8;

while ( true )

{

readLen = read(sockfd, buf, nReadLen);

// printf( "read: %d/n", readLen );

if (readLen < 0 && errno == EINTR)

{

continue;

}

else if ( readLen <= 0 )

{

perror( "read:");

return -1;

}

else

{

nReadLen -= readLen;

if (nReadLen <= 0 )

{

break;

}

}

}

printf( "read response successed./n" );

return 0;

}

int main(int argc, char **argv)

{

printf("client ip: %s/n", argv[1]);

printf("client port: %s/n", argv[2]);

printf("server ip: %s/n", argv[3]);

printf("server port: %s/n", argv[4]);

printf("/n service starting.../n/n");

while( true )

{

int socketFd;

struct sockaddr_in svrAddr;

struct sockaddr_in localAddr;

socketFd = socket (AF_INET, SOCK_STREAM, 0);

if ( -1 == socketFd )

{

perror( "socket:" );

continue;

}

// 设置地址可复用

int option = 1;

setsockopt( socketFd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) );

// 客户端IP

memset(&localAddr, 0, sizeof(localAddr));

localAddr.sin_family = AF_INET;

localAddr.sin_addr.s_addr = inet_addr( argv[1]);

localAddr.sin_port = htons (atoi(argv[2]));

int bindResult = bind(socketFd, (struct sockaddr *) &localAddr, sizeof(localAddr));

if ( -1 == bindResult )

{

perror( "bind:" );

sleep(10);

close(socketFd);

continue;

}

// 服务器IP

memset(&svrAddr, 0, sizeof(svrAddr));

svrAddr.sin_family = AF_INET;

svrAddr.sin_addr.s_addr = inet_addr( argv[3]);

svrAddr.sin_port = htons (atoi(argv[4]));

// 不断重连

int connResult = connect(socketFd, (struct sockaddr *) &svrAddr, sizeof(svrAddr));

if ( -1 == connResult )

{

perror( "connect:" );

sleep(10);

close(socketFd);

continue;

}

printf (" connect %s:%s successed./n", argv[3], argv[4] );

static unsigned short no = 0;

// 连接成功，每分钟发送一次数据

for ( ; ; )

{

if ( -1 == str_echo(socketFd, no++) )

{

break;

}

sleep( 60 );

}

close(socketFd);

}

}

tcp服务器源码示例

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

struct _NSS_HEADER

{

unsigned short ProtocolVersion; /* 协议版本信息 */

unsigned short MsgType; /* 消息类型 */

unsigned short TransactionNo; /* 传输编号 */

unsigned short PacketLength; /* 数据包长度,包括Header */

}NSS_HEADER;

void str_echo(int sockfd)

{

ssize_t readLen;

ssize_t writeLen;

char buf[8];

while ( true )

{

readLen = read(sockfd, buf, 8);

if (readLen < 0 && errno == EINTR)

{

continue;

}

else if ( readLen <= 0 )

{

perror( "read:");

return ;

}

printf( "recv data successed. data len: %d/n", readLen );

int nWriteLen = 0;

while ( true )

{

writeLen == write(sockfd, &buf[nWriteLen], readLen-nWriteLen);

if (writeLen < 0 && errno == EINTR)

{

continue;

}

else if ( writeLen < 0 )

{

perror ( "write:" );

return;

}

nWriteLen += writeLen;

// 已写完，直接返回

if (nWriteLen >= readLen )

{

break;

}

}

printf( "send data successed. data len: %d/n", readLen );

}

}

int main(int argc, char **argv)

{

printf( "server ip: %s/n", argv[1] );

printf( "server port: %s/n", argv[2] );

printf( "/nservice starting ... /n/n" );

int listenfd, connfd;

pid_t childpid;

socklen_t clilen;

struct sockaddr_in cliaddr, servaddr;

listenfd = socket (AF_INET, SOCK_STREAM, 0);

if ( -1 == listenfd )

{

perror( "socket:" );

exit(-1);

}

// 设置地址可复用

int option = 1;

setsockopt( listenfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) );

memset(&servaddr, 0, sizeof(servaddr));

servaddr.sin_family = AF_INET;

servaddr.sin_addr.s_addr = inet_addr( argv[1]);

servaddr.sin_port = htons (atoi(argv[2]));

int bindResult = bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));

if ( -1 == bindResult )

{

perror( "bind:" );

exit(-1);

}

int listenResult = listen(listenfd, 5);

if ( -1 == listenResult )

{

perror( "listen:" );

exit(-1);

}

for ( ; ; )

{

clilen = sizeof(cliaddr);

connfd = accept(listenfd, (struct sockaddr *) &cliaddr, &clilen);

if ( -1 == connfd )

{

perror( "accept:" );

continue;

}

printf ("accept %s successed.fd: %d/n", inet_ntoa(cliaddr.sin_addr), connfd );

if ( (childpid = fork()) == 0)

{ /* child process */

close(listenfd); /* close listening socket */

str_echo(connfd); /* process the request */

printf ("disconnect from %d ./n", connfd );

exit (0);

}

}

close(connfd); /* parent closes connected socket */

}