client.c

面向的是lpc2000系列arm,周立功magic arm 提供的TCP通讯实验代码

#include <stdio.h> 
#include <stdlib.h>
#include <errno.h> 
#include <string.h> 
#include <netdb.h> 
#include <sys/types.h> 
#include <netinet/in.h> 
#include <sys/socket.h> 

#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 ("ERROR: Please enter Host IP address follow by 'gdclient'\n");
        return (0);
    }

    /* Get the Socket file descriptor */
    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
    {
        printf("ERROR: Cannot 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: Cannot 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);
}