Internet Technologies and Techniques
Top level of stack
(Application layer protocols, protocol = established agreed way of sharing info)
HTTP, FTP, RTSP, IMAP/POP...
using telnet in terminal to connect to sputnik.media.aalto.fi
Commands in terminal -
telnet sputnik.media.aalto.fi 80
GET http://sputnik.media.aalto.fi/ HTTP/1.0
port 80, default port for HTTP connections. IMAP/POP, port 143
DNS = domain name server, basically a server that knows what name links to what ip address of the server.
For eg. to access sputnik.media.aalto.fi, TLD = top level DNS which redirects to local .fi DNS which would send to aalto DNS so on...
Look up - ICANN,
TCP Transmission control protocol Checks for connections, if everything is ok, errors etc., it guarantees that the information that is requested, will be received in whole without drops etc. retransmits lost packages.
UDP user datagram protocol = gets the data as fast as possible, but no guarantees for drops or right order etc., no error correction.
Internet layer, handles routing of connections , independent of hardware. Traceroute in terminal/network utility shows the routes through multiple servers.
ssh in terminal is the way to connect to a remote computer.
ls lists files on the computer.
nano, text editor for terminal.
using PHP to make a random counter
Using PHP to implement web store basics.
using databases to manage the webstore. We will be using LAMP stack for managing this. LAMP = linux, apache, mySQL, php
$ mysql -u php-server -p , means that we will me authenticating user php with a password. ' my sql commands are always in all caps and are followed by semicolons at the end. for eg. SHOW DATABASE;
Creating a atable in a database,
mysql> CREATE TABLE `person` (
-> `id` INT UNSIGNED AUTO_INCREMENT, -> `first_name` VARCHAR(250) COLLATE UTF8_SWEDISH_CI, -> `last_name` VARCHAR(250) COLLATE UTF8_SWEDISH_CI, -> PRIMARY KEY (`id`) -> );
USE BACK TICKS AND NOT APOSTROPHES. ``````````````````````vs '''''''''''''''''''''''''''''''''''
populating tables mysql> INSERT INTO person (first_name, last_name)
-> VALUES ('s', 'k');
deleting someone mysql> DELETE FROM person WHERE id='1';
Changing user id mysql> UPDATE person
-> SET first_name='name', last_name='bleh' -> WHERE id='2';
Adding a row to existing database mysql> ALTER TABLE person
-> ADD `adress` VARCHAR(250) COLLATE UTF8_SWEDISH_CI;
To make alterations within tables ALTER TABLE person CHANGE `adress` `address` VARCHAR(250) COLLATE UTF8_SWEDISH_CI;
Using phpmyadmin for creating and populating databases
creating store front.
in nano editor --->
<?php $database = "localhost"; $username = "php-server"; $password = "password";
$connection = new mysqli($database, $username, $password);
die("connection failed: " . $connection->connect_error);
} echo "Connected succesfully";
<!DOCTYPE html> <head>
<body> this is going to be my webstore </body>