client.c

Linux网络编程第一个实验,使用TCP协议实现了服务器和客户端

/***
*****Filename:client.c
*****Author:Will
*****E-Mail:[e-mail]
*****Date:2008-05-26
*****Version:Beta 0.0
*****Remark:HNU
***/

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


#define PORTNUM         9000          // Port number
//#define HOSTNAME        "127.0.0.1"   //Host IP

int main(int argc,char *argv[])
{ 
  FILE *fp;
  char *ch = NULL;
  int n,size, ServerSock ;				// Socket bound to the server
  char fileName[256];
  char buffer[900*1024];				 //Send buffer
  struct sockaddr_in destination_sin;        // Server socket address
  struct hostent *phostent;           		// Points to the HOSTENT structure of the server
  char HOSTNAME[18];
    

  if (argc < 2)
  {
	fprintf (stderr, "Usage Error! \nUsage : ./client  FileName  down/up(download or upload)   HostIP   \nPlease Try Again.\n");
	exit (1);
  }
  
  strcpy (HOSTNAME, argv[3]); 
    
  // Create a TCP/IP socket that is bound to the server.
  if ((ServerSock = socket (AF_INET, SOCK_STREAM, 0)) < 0)
  {
    fprintf (stderr, "Allocating socket failed.\n");
    exit(1);
  }

  // Fill out the server socket's address information.
  destination_sin.sin_family = AF_INET;

  // Assign the socket IP address.
  destination_sin.sin_addr.s_addr=inet_addr(HOSTNAME);

  // Convert to network ordering.
  destination_sin.sin_port = htons (PORTNUM);      

  // Establish a connection to the server socket.
  if (connect (ServerSock, 
               (struct sockaddr *) &destination_sin, 
               sizeof (destination_sin)) <0) 
  {
    fprintf (stderr,"Connecting to the server failed.\n");
    close(ServerSock);
    exit(1);
  }

	  ch = strrchr (argv[1], '/'); // ch point to the last '/'

	  if ((ch != NULL) && (strlen(ch) > 0))//if the argument 1 contains the full path and the last char is not '/'
	  {
		ch++;
		strcpy (fileName, ch); //copy the file name to  fileName
	  }
	  else //if the argument 1 is the file name
	  {
		strcpy (fileName, argv[1]); // get the file name
	  }


 if(strcmp(argv[2],"up")==0)//upload file
  {
	  //try to open the file
	   if( (fp  = fopen(argv[1], "r" )) == NULL )

	  {
		fprintf( stderr, "The file was not opened\n" );
		exit (1);
	  }

	   printf ("Uploading file %s to %s ...\n", fileName, HOSTNAME);

	  // sending request
	  if (send (ServerSock, "up", 3 , 0) <0)
	  {
		  fprintf(stderr, "Sending request error \n");
		  exit (1);
	  }
		printf("Sending request...\n");
	   // sending filename
	  if (send (ServerSock, fileName, strlen(fileName) + 1, 0) <0)
	  {
		  fprintf(stderr, "Sending file name error \n");
		  exit (1);
	  }
	  	printf("Sending file name...\n");
	  //sending once a char
	  while((size = fread(buffer,sizeof(char),sizeof(buffer), fp))>0)
	  {
		printf(".");
  		if (send (ServerSock, buffer, size, 0) < 0)
  		{
  		  fprintf (stderr,"Sending data to the server failed.\n");
  		}
	  }
	 	 printf("Sending data...\n");
	  // Disable sending on ServerSock.
	  close(ServerSock);
	  
	  printf ("Uploading finished\n");
  }
 else if(strcmp(argv[2],"down")==0)//download file 
 {
	  fp = fopen (fileName, "w+"); //create file
	  if (fp == NULL)
	  {
	    printf("Create File Error! \nfilename : %s \n",fileName);
	    exit (1);
	  }
	
	// sending request
	  if (send (ServerSock, "dn", 3 , 0) <0)
	  {
		  fprintf(stderr, "Sending request error \n");
		  exit (1);
	  }
		printf("Sending request...\n");
 	// sending filename
	  if (send (ServerSock, fileName, strlen(fileName) + 1, 0) <0)
	  {
		  fprintf(stderr, "Sending file name error \n");
		  exit (1);
	  }
	  	printf("Sending file name...\n");

 	while ((n = read(ServerSock, buffer, 1024)) >= 0)
	  {
	    if (n > 0)
	    { 
	      fwrite (buffer, sizeof(char), n, fp);
	    }
	    else 
	    {
	       fclose (fp);
	       break;
	    }
	}
	  if (n < 0) 
	  {
	    fclose (fp);
	    printf("Read data from network error!\n");
	    exit (1);
	  }	  
	printf("Recieving data...\n");
	  // Disable sending on ServerSock.
	  close(ServerSock);
	  
	  printf ("Downloading finished\n");
 }

  exit(0);
}