server.c

/* A simple server in the internet domain using TCP
The port number is passed as an argument */

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

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

int main(int argc, char *argv[])
{
	int sockfd, newsockfd, portno;
	socklen_t clilen;
	char buffer[256];
	struct sockaddr_in serv_addr, cli_addr;
	int n;
	

	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0) 
	error("ERROR opening socket");
	bzero((char *) &serv_addr, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = INADDR_ANY;
	serv_addr.sin_port = htons(1234);
	if (bind(sockfd, (struct sockaddr *) &serv_addr,
	      sizeof(serv_addr)) < 0) 
	      error("ERROR on binding");
	listen(sockfd,5);
	clilen = sizeof(cli_addr);
	newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
	if (newsockfd < 0) 
	  error("ERROR on accept");
	bzero(buffer,256);

	n = read(newsockfd,buffer,255);

	if (n < 0) error("ERROR reading from socket");
	printf("Here is the message: %s\n",buffer);

	close(newsockfd);
	close(sockfd);
	return 0; 
}