Untitled

# simple web server using sockets

import re
import socket
import sys
import time

html = """<html>
<body>
Hi - this is my html
</body>
</html>
"""


def NBRecv(conn):
    """
    Non blockeing recv from socket.
    return empty string if nothing to recv
    :param conn:
    :return:
    """
    data = ""
    try:
        buf = conn.recv(1024)
        while buf:
            data += buf
            buf = conn.recv(1024)
    except socket.error:
        pass
    return data


def SendHtml(conn, html):
    """
    Send html header and html text on the connection
    :param conn:
    :param html:
    :return:
    """
    content_len = len(html)
    header = {}
    header["Content-Length"] = str(content_len)
    header["Content-Type"] = "text/html"
    header["Connection"] = "Closed"
    response_line = "HTTP/1.1 200 OK\r\n"
    header_pairs = [k + ": " + v for k,v in header.iteritems()]
    header_text = "\r\n".join(header_pairs)
    header_full = response_line + header_text + "\r\n\r\n"
    conn.send(header_full + html)


def HandleConnection(conn):
    """
    Handle single connection - parse http request
    :param conn:
    :return:
    """
    # return True if you want to close conn
    request = NBRecv(conn)
    if not request:
        # no data on this connection - keep trying
        return False
    print request
    lines = request.splitlines()
    m = re.match(r"(GET|POST) (/\S*) HTTP/1\.(1|0)", lines[0])
    if not m:
        conn.send("HTTP/1.1 400 Bad Request\r\n")
        return True
    resource = m.group(2)
    if resource != "/":
        conn.send("HTTP/1.1 404 Not found\r\n")
        return True
    SendHtml(conn, html)
    return True


def HandleConnections(connections):
    for conn in connections:
        if HandleConnection(conn):
            conn.close()

def WebServer(port):
    accept_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    accept_socket.bind(("", port))
    accept_socket.listen(5)
    accept_socket.setblocking(0)
    connections = []
    while True:
        try:
            conn, addr = accept_socket.accept()
            print 'Connected by', addr
            connections.append(conn)
        except socket.error:
            time.sleep(0)  # give some time if no connection waiting
            pass
        HandleConnections(connections)


def main(argv):
    port = 8081
    if len(argv) > 1:
        port = int(argv[1])
    WebServer(port)


if __name__ == '__main__':
    sys.exit(main(sys.argv))