Revision as of 03:06, 1 July 2011

The browser is the new GUI!

Serve our standard text "Goodbye, World!" to http://localhost:8080/ so that it can be viewed with a web browser.

Starting a web browser or opening a new window with this URL is not part of the task. Also you do not need to bother serving proper HTML, as browsers generally do the right thing with simple text like this. Your program must however, start or implement a server that accepts multiple client connections and serves text as requested.

C

Well, this is, um, slightly longer than what other languages would be. <lang C>#include <stdio.h>

include <stdlib.h>
include <omp.h>
include <unistd.h>
include <sys/types.h>
include <sys/socket.h>
include <sys/wait.h>
include <signal.h>
include <netinet/in.h>
include <netdb.h>
include <arpa/inet.h>
include <err.h>

char canned_response[] = "HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=UTF-8\r\n\r\n<html><head><title>Goodbye, world!</title><style>h1{font-size:4cm; color: red; text-shadow: .2cm .2cm black}</style></head><body>

Goodbye, world!

</body></html>\r\n";

void reap(int x) { while(waitpid(-1, 0, WNOHANG) > 0); }

int do_server_stuff() { int sock = socket(AF_INET, SOCK_STREAM, 0); int one = 1; int client_fd; socklen_t sin_len; struct sigaction sac; char msg_in[4096];

if (sock < 0) err(1, "can't open socket"); setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(int));

int port = 8080; struct sockaddr_in svr_addr, cli_addr; 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) { close(sock); err(1, "Can't bind"); }

listen(sock, 5);

sac.sa_handler = reap; sigemptyset(&sac.sa_mask); sac.sa_flags = SA_RESTART; if (sigaction(SIGCHLD, &sac, 0) == -1) err(1, "can't install signal handler");

while (1) { client_fd = accept(sock, (struct sockaddr *) &cli_addr, &sin_len); if (client_fd == -1) { perror("Can't accept"); continue; } if (!fork()) { /* child here */ close(sock); if (read(client_fd, msg_in, 4096) == -1) { perror("read failure"); } write(client_fd, canned_response, sizeof(canned_response) - 1);/*-1:'\0'*/ close(client_fd); exit(0); }

printf("got connection\n"); close(client_fd); } }

int main() { do_server_stuff(); return 0; }</lang>

Go

<lang go>package main

import (

   "http"
   "fmt"

)

func main() {

   http.HandleFunc("/",
       func(w http.ResponseWriter, req *http.Request) {
           fmt.Fprintln(w, "Goodbye, World!")
       })
   if err := http.ListenAndServe(":8080", nil); err != nil {
       fmt.Println(err)
   }

}</lang>