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

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

#define MY_PORT         9000

int main(int argc ,char **argv) 
{ 
 int size,listen_fd,accept_fd; 
 struct sockaddr_in     client_addr; 
 int n; 
 FILE *fp;
  
 struct sigaction sa;
 memset(&sa,'\0',sizeof(sigaction)); 
 sa.sa_handler=SIG_IGN;
 sa.sa_flags=SA_NOCLDSTOP;

 sigaction(SIGCHLD,&sa,NULL );

 if((listen_fd=socket(AF_INET,SOCK_STREAM,0))<0) 
  { 
        printf("Socket Error:%s\n\a",strerror(errno)); 
        exit(1); 
  } 
  
 bzero(&client_addr,sizeof(struct sockaddr_in)); 
 client_addr.sin_family=AF_INET; 
 client_addr.sin_port=htons(MY_PORT); 
 client_addr.sin_addr.s_addr=htonl(INADDR_ANY); 
 n=1; 
 setsockopt(listen_fd,SOL_SOCKET,SO_REUSEADDR,&n,sizeof(int)); 
 if(bind(listen_fd,(struct sockaddr *)&client_addr,sizeof(client_addr))<0) 
  { 
        printf("Bind Error:%s\n\a",strerror(errno)); 
        exit(1); 
  } 
  listen(listen_fd,5); 
  printf("Listening to the connect request of client......\n");

  while(1) 
  { 
   accept_fd=accept(listen_fd,NULL,NULL); 
   if((accept_fd<0)&&(errno==EINTR)) 
          continue; 
   else if(accept_fd<0) 
    { 
        printf("Accept Error:%s\n\a",strerror(errno)); 
        continue; 
    } 
    
  if((n=fork())==0) 
   { 
   	char  *tmp = NULL;
	char  *dou=NULL;
        char buffer[200*1024]   = {0}; 
	char req[3]={0};
	char s_buffer[200*1024]   = {0}; //recieve file 
        close(listen_fd); 
	//recieve request
	n=read(accept_fd,req,3); 
	printf("Begining to recieve request......\n");
	dou = strchr (req,'\0');//find '\0' in request
	if( dou!=NULL && strcmp("up",req)==0 )
	{
        n=read(accept_fd,buffer,1024); 
	printf("filename : %s request : %s\n",buffer,req);
        printf("Begining to recieve the file......\n");
	
	tmp = strchr (buffer,'\0');//find '\0' in buffer
	
	if (tmp != NULL) // '\0' exist in buffer
	{
	  fp = fopen (buffer, "w+"); // open or create file 
	  if (fp == NULL)
	  {
	    printf("Create File Error! \nfilename : %s request : %s\n",buffer,req);
	    exit (1);
	  }
	  
	  if (strlen(buffer) < (n - 1))// something more than filename in buffer 
	  {
	    tmp++;//ָjump next to the '\0'
	    fwrite (tmp, sizeof(char), n - strlen(buffer) - 1, fp);// write content to the file
	  }
	  
	  while ((n = read(accept_fd, buffer, 1024)) >= 0) // read once a char
	  {
	    if (n > 0) 
	    { 
	      fwrite (buffer, sizeof(char), n, fp);//write to the file
	    }
	    else 
	    {
	       fclose (fp);
	       break;
	    }
	  }
	  
	  if (n < 0) // erro
	  {
	    fclose (fp);
	    printf("Read data from network error!\n");
	    exit (1);
	  }	  
	  printf("File transfer successfully!......\n");

	} 
	
        close(accept_fd); 
        exit(0); 
	}
	else if(dou!=NULL && strcmp("dn",req)==0)
	{
	 n=read(accept_fd,buffer,1024); 
	printf("filename : %s request : %s\n",buffer,req);
	  //try to open the file
	   if( (fp  = fopen(buffer, "r" )) == NULL )

	  {
		fprintf( stderr, "The file was not opened\n" );
		exit (1);
	  }
	  //sending once a char
	  while((size = fread(s_buffer,sizeof(char),sizeof(s_buffer), fp))>0)
	  {
		printf(".");
  		if (send (accept_fd, s_buffer, size, 0) < 0)
  		{
  		  fprintf (stderr,"Sending data to the server failed.\n");
  		}
	  }
	 	 printf("Sending data...\n");
        close(accept_fd); 
        exit(0); 
	}
	else
	{
	printf("Accept request Error!\n");
	exit (1);
	}
   } 
   else if(n<0) 
        printf("Fork Error:%s\n\a",strerror(errno)); 
   close(accept_fd); 
   
} 
  printf("\nReceive finished,press any key to return\n");

   getch();

}