C++: Hello World Web Server


The browser is the new GUI !

The task is to serve our standard text “Goodbye, World!” to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.

Note that starting a web browser or opening a new window with this URL is not part of the task.
Additionally, it is permissible to serve the provided page as a plain text file (there is no requirement to serve properly formatted HTML here). The browser will generally do the right thing with simple text like this.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <err.h>

char response[] = "HTTP/1.1 200 OK\r\n"
"Content-Type: text/html; charset=UTF-8\r\n\r\n"
"<!DOCTYPE html><html><head><title>Bye-bye baby bye-bye</title>"
"<style>body { background-color: #111 }"
"h1 { font-size:4cm; text-align: center; color: black;"
" text-shadow: 0 0 2mm red}</style></head>"
"<body><h1>Goodbye, world!</h1></body></html>\r\n";

int main()
	int one = 1, client_fd;
	struct sockaddr_in svr_addr, cli_addr;
	socklen_t sin_len = sizeof(cli_addr);

	int sock = socket(AF_INET, SOCK_STREAM, 0);
	if (sock < 0)
	err(1, "can't open socket");

	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(int));

	int port = 8080;
	svr_addr.sin_family = AF_INET;
	svr_addr.sin_addr.s_addr = INADDR_ANY;
	svr_addr.sin_port = htons(port);

	if (bind(sock, (struct sockaddr *) &svr_addr, sizeof(svr_addr)) == -1) {
		err(1, "Can't bind");

	listen(sock, 5);
	while (1) {
		client_fd = accept(sock, (struct sockaddr *) &cli_addr, &sin_len);
		printf("got connection\n");

		if (client_fd == -1) {
			perror("Can't accept");

		write(client_fd, response, sizeof(response) - 1); /*-1:'\0'*/


Content is available under GNU Free Documentation License 1.2.