myftpd.c

#include<stdio.h>
#include<string.h> 
#include<stdlib.h> 
#include<sys/socket.h>
#include<arpa/inet.h>
#include<unistd.h>

#define QUEUE 1				//Queue for incoming connections
#define BUFFLENGTH 512      //Send buffer length

int main(int argc , char *argv[])
{
    int sock_fd, len, newsock, readsize;
    struct sockaddr_in server, client;
    FILE *fp;
    char *file = "oven.f";
    char buffr[BUFFLENGTH];

    if(argc < 2)
    {
    	printf("Too few arguments. \nUsage : myftpd <port>\n");
    	exit(1);
    }

    int port = atoi(argv[1]);

    sock_fd = socket(AF_INET , SOCK_STREAM , 0);    
     
    if (sock_fd == -1)
    {
        printf("Could not create socket!\n");
    }
    
    //Prepare the sockaddr_in structure
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;
    server.sin_port = htons(port);
     
    //Bind
    if( bind(sock_fd,(struct sockaddr *)&server , sizeof(server)) < 0)
    {
        printf("Server bind failed!\n");
        return 1;
    }
 
    listen(sock_fd , QUEUE);
    printf("Waiting for SYN\n");

    while (newsock = accept(sock_fd, (struct sockaddr *)&client, (socklen_t*)&len)){
        printf("New connect from %s.\n", inet_ntoa(client.sin_addr));        
        
        fp = fopen(file, "r");

        if(fp == NULL)
        {
            printf("File 404'd \n");
            return 1;
        }        

        bzero(buffr, BUFFLENGTH);
        while((readsize = fread(buffr, sizeof(char), BUFFLENGTH, fp)) > 0)
        {
            int sentbytes;
            sentbytes = send(newsock, buffr, readsize, 0);
            if(sentbytes < 0)
            {
                printf("Send to client failed.\n");
            }
            else if(sentbytes >= readsize) {
                close(newsock);
            }
            bzero(buffr, BUFFLENGTH);
        }
    }
	if (newsock < 0 ){
		printf("Something went wrong\n");
	}
	printf("File sent. So long, and thanks for the fish... \n");
	close(sock_fd);
}