linux下TCP编程

2009-09-21 22:24

编程要求:
客户端建立连接，服务器端接受连接并向客户端发送消息，客户端接收消息并将消息打印出来，最后服务器端向客户端发送exit，连接结束！

源代码：
//服务器端:server.c

#include
#include
#include
#include
#include
#include
#include
#include

#define PORT 5000                      // The port which is communicate with server
#define BACKLOG 10
#define LENGTH 512                     // Buffer length
int main ()
{   int sockfd;                        // Socket file descriptor
int nsockfd;                       // New Socket file descriptor
int num;
int sin_size;                      // to store struct size
char sdbuf[LENGTH];                // Send buffer
struct sockaddr_in addr_local;
struct sockaddr_in addr_remote;
char sendstr[16]= {"123456789 abcde"};

/* Get the Socket file descriptor */
if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1 )
{
printf ("ERROR: Failed to obtain Socket Despcritor.\n");
return (0);
}
else
{
printf ("OK: Obtain Socket Despcritor sucessfully.\n");
}

/* Fill the local socket address struct */
addr_local.sin_family = AF_INET;           // Protocol Family
addr_local.sin_port = htons(PORT);         // Port number
addr_local.sin_addr.s_addr = INADDR_ANY; // AutoFill local address
bzero(&(addr_local.sin_zero), 8);          // Flush the rest of struct

/* Blind a special Port */
if( bind(sockfd, (struct sockaddr*)&addr_local, sizeof(struct sockaddr)) == -1 )
{
printf ("ERROR: Failed to bind Port %d.\n",PORT);
return (0);
}
else
{
printf("OK: Bind the Port %d sucessfully.\n",PORT);
}

/* Listen remote connect/calling */
if(listen(sockfd,BACKLOG) == -1)
{
printf ("ERROR: Failed to listen Port %d.\n", PORT);
return (0);
}
else
{
printf ("OK: Listening the Port %d sucessfully.\n", PORT);
}

while(1)
{
sin_size = sizeof(struct sockaddr_in);

/* Wait a connection, and obtain a new socket file despriptor for single connection */
if ((nsockfd = accept(sockfd, (struct sockaddr *)&addr_remote, &sin_size)) == -1)
{
printf ("ERROR: Obtain new Socket Despcritor error.\n");
continue;
}
else
{
printf ("OK: Server has got connect from %s.\n", inet_ntoa(addr_remote.sin_addr));
}

/* Child process */
if(!fork())
{
printf("You can enter string, and press 'exit' to end the connect.\n");
while(strcmp(sdbuf,"exit") != 0)
{
scanf("%s", sdbuf);
if((num = send(nsockfd, sdbuf, strlen(sdbuf), 0)) == -1)
{
printf("ERROR: Failed to sent string.\n");
close(nsockfd);
exit(1);
}
printf("OK: Sent %d bytes sucessful, please enter again.\n", num);
}
}
close(nsockfd);
while(waitpid(-1, NULL, WNOHANG) > 0);
}
}

//客户端：client.c

#include
#include
#include
#include
#include
#include
#include
#include

#define PORT 5000                      // The port which is communicate with server
#define LENGTH 256                     // Buffer length

int main(int argc, char *argv[])
{
int sockfd;                        // Socket file descriptor
int num;                           // Counter of received bytes
char revbuf[LENGTH];               // Receive buffer
struct sockaddr_in remote_addr;    // Host address information

/* Check parameters number */
if (argc != 2)
{
printf ("Usage: client HOST IP (ex: ./client 192.168.0.94).\n");
return (0);
}

/* Get the Socket file descriptor */
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
printf("ERROR: Failed to obtain Socket Descriptor!\n");
return (0);
}

/* Fill the socket address struct */
remote_addr.sin_family = AF_INET;                   // Protocol Family
remote_addr.sin_port = htons(PORT);                 // Port number
inet_pton(AF_INET, argv[1], &remote_addr.sin_addr); // Net Address
bzero(&(remote_addr.sin_zero), 8);                  // Flush the rest of struct

/* Try to connect the remote */
if (connect(sockfd, (struct sockaddr *)&remote_addr, sizeof(struct sockaddr)) == -1)
{
printf ("ERROR: Failed to connect to the host!\n");
return (0);
}
else
{
printf ("OK: Have connected to the %s\n",argv[1]);
}

/* Try to connect the server */
while (strcmp(revbuf,"exit") != 0)     // Check remoter command
{
bzero(revbuf,LENGTH);
num = recv(sockfd, revbuf, LENGTH, 0);

switch(num)
{
case -1:
printf("ERROR: Receive string error!\n");
close(sockfd);
return (0);

case 0:
close(sockfd);
return(0);

default:
printf ("OK: Receviced numbytes = %d\n", num);
break;
}

revbuf[num] = '\0';
printf ("OK: Receviced string is: %s\n", revbuf);
}
close (sockfd);
return (0);
}

结果：

1:[root@localhost server]# ./server
OK: Obtain Socket Despcritor sucessfully.
OK: Bind the Port 5000 sucessfully.
OK: Listening the Port 5000 sucessfully.
2:[root@zylinux uclient]# ./client 192.168.0.94

OK: Have connected to the 192.168.0.94

[root@localhost server]
OK: Server has got connect from 192.168.0.231.
You can enter string, and press 'exit' to end the connect.

3:在PC终端输入
hello moon!
显示：
OK: Sent 8 bytes sucessful, please enter again.
OK: Sent 5 bytes sucessful, please enter again.

在客户端会显示
OK: Receviced numbytehello
OK: Receviced numbytes = 5
OK: Receviced string is: moon!

4在PC终端输入 exit
显示
OK: Sent 4 bytes sucessful, please enter again.
客户端显示：
OK: Receviced numbytes = 4
OK: Receviced string is: exit
[root@zylinux uclient]# 即跳出了

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linux下TCP编程(转)

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