Socket Programming

Socket Programming

Sending File and Receiving file using FTP

First Read the Instruction

Open 2 terminal
go to directory file server and client
client-> gcc -o client client.c
server-> gcc -o server server.c
server-> ./server 20000
client-> ./client 20000
if any thing worng happen change the path in program both server and client

Server.c

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

#define PORT 20000 
#define BACKLOG 5
#define LENGTH 1024 

void error(const char *msg){
perror(msg);
exit(1);

}
int main(){

 int sockfd; 
 int nsockfd; 
 int num;
 int sin_size; 
 struct sockaddr_in addr_local; //client address
 struct sockaddr_in addr_remote;//server address
 char revbuf[LENGTH];//recieve buf

if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1 ){
 error("Error: socket creation\n");
}
else printf("socket creation success");


addr_local.sin_family = AF_INET; //ipv4 used
addr_local.sin_port = htons(PORT);
addr_local.sin_addr.s_addr = INADDR_ANY; // AutoFill local address
bzero(&(addr_local.sin_zero), 8); // Flush the rest of struct


if( bind(sockfd, (struct sockaddr*)&addr_local, sizeof(struct sockaddr)) == -1 ){
     error("Error in port binding\n");
 }
 else 
  printf("[Server] Binded port %d in addr 127.0.0.1 sucessfully.\n",PORT);

if(listen(sockfd,BACKLOG) == -1){
     error("ERROR: Failed to listen Port.\n");
 }
 else
  printf ("[Server] Listening the port %d successfully.\n", PORT);

 int success = 0;
while(success == 0)
 {
     sin_size = sizeof(struct sockaddr_in);


if ((nsockfd = accept(sockfd, (struct sockaddr *)&addr_remote, &sin_size)) == -1){
         error("ERROR: Obtaining new Socket Despcritor.\n");
  }
     else printf("[Server] Server has got connected from %s.\n", inet_ntoa(addr_remote.sin_addr));

//printf("Enter path of the file:\n"):
char* fs_name= "/home/omy/ssss/CP/server-client/server/temps.txt";//Path
char sdbuf[LENGTH]; // Send buffer
printf("[Server] Sending %s to the Client...", fs_name);
            FILE *fs = fopen(fs_name, "r");
            if(fs == NULL)
            {
                fprintf(stderr, "ERROR: File %s not found on server. (errno = %d)\n", fs_name, errno);
                exit(1);
            }

            bzero(sdbuf, LENGTH); 
            int fs_block_sz;
while((fs_block_sz = fread(sdbuf, sizeof(char), LENGTH, fs))>0)
            {
                if(send(nsockfd, sdbuf, fs_block_sz, 0) < 0)
                {
                    fprintf(stderr, "ERROR: Failed to send file %s. (errno = %d)\n", fs_name, errno);
                    exit(1);
                }
                bzero(sdbuf, LENGTH);
            }
            printf("Ok sent to client!\n");
            success = 1;
            close(nsockfd);
            printf("[Server] Connection with Client closed. Server will wait now...\n");
            while(waitpid(-1, NULL, WNOHANG) > 0);
}

return 0;
}

Client.c

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

#define PORT 20000 
#define BACKLOG 5
#define LENGTH 1024 

void error(const char *msg){
perror(msg);
exit(1);

}
int main(int argc,char *argv[]){
 
 int sockfd; 
 int nsockfd;
 char revbuf[LENGTH]; 
 struct sockaddr_in remote_addr;

if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1){
     error("Error in socket creation\n");
 }
else printf("socket creation success");

 remote_addr.sin_family = AF_INET; 
 remote_addr.sin_port = htons(PORT); 
 inet_pton(AF_INET, "127.0.0.1", &remote_addr.sin_addr); 
 bzero(&(remote_addr.sin_zero), 8);

if (connect(sockfd, (struct sockaddr *)&remote_addr, sizeof(struct sockaddr)) == -1)
 {
     error("ERROR: Failed to connect to the host!\n");
 }
 else 
  printf("[Client] Connected to server at port %d...ok!\n", PORT);


//if(!fork())
 //{

 char* fs_name = "/home/omy/ssss/CP/server-client/client/dest.txt";
  char sdbuf[LENGTH]; 
  printf("[Client] Sending %s to the Server...", fs_name);
  FILE *fs = fopen(fs_name, "r");
  if(fs == NULL)
  {
      printf("ERROR: File %s not found.\n", fs_name);
   exit(1);
  }

  bzero(sdbuf, LENGTH); 
  int fs_block_sz; 
//int success = 0;

while((fs_block_sz = fread(sdbuf, sizeof(char), LENGTH, fs))>0)
     {
         if(send(sockfd, sdbuf, fs_block_sz, 0) < 0)
         {
             printf("ERROR: Failed to send file %s.\n", fs_name);
             break;
         }
         bzero(sdbuf, LENGTH);
     }
     printf("Ok File %s from Client was Sent!\n", fs_name);
     //success = 1;
  //}


printf("[Client] Receiveing file from Server and saving it as final.txt...");
 char* fr_name = "/home/omy/ssss/CP/server-client/client/final.txt";//Path

 FILE *fr = fopen(fr_name, "a");
 if(fr == NULL)
  printf("File %s Cannot be opened.\n", fr_name);
 else
 {
     bzero(revbuf, LENGTH); 
     int fr_block_sz = 0;
     int success = 0;

 //while(success == 0)
 //{
   while(fr_block_sz = recv(sockfd, revbuf, LENGTH, 0))
         {
             if(fr_block_sz < 0)
             {
                 error("Receive file error.\n");
             }
             int write_sz = fwrite(revbuf, sizeof(char), fr_block_sz, fr);
             if(write_sz < fr_block_sz)
             {
                 error("File write failed.\n");
             }
    else if(fr_block_sz)
    {
     break;
    }
             bzero(revbuf, LENGTH);
         }
         printf("Ok received from server!\n");
         success = 1;
         fclose(fr);
//}


 }
close (sockfd);
 printf("[Client] Connection lost.\n");
 return (0);
}

                                            Give Something to the world and it will never let you down. 

                                                                                                 Onkar Dubey