1.3 html and web servers

Module 4: web server and web pages (html)

see also https://elab.hpa.edu/cs/TC/TC%205.0%20HTML.pdf

Background:

• html stands for hypertext markup language
• it is a markup language, not really programming like python or C
• it manages how information is presented ("marked up") for viewers
• others include xml and xhtml, both managing data as well as format (more on this soon)

Installing a web server:

1. On the raspberry pi, run the following commands:
   
2. sudo apt-get update (this updates your computer)
   
3. sudo apt-get install apache2 -y (this installs apache web server on your computer, answering yes to all prompts)
   
4. Go your browser and enter 127.0.0.1 (which means "me" on the internet)
   
5. Now type ifconfig in your terminal and look for your internet address, which should start with 10.14.x.y
   
6. Look at this address using your browser
   

Setup your web folder, edit a page:

• changing the home page, which is always index.html on any web server:

1. On the terminal, navigate to the following directory:
   
2. cd /var/www/html/
   
3. run the ls command, you should see a file called index.html
   
4. You can edit this, either by using the nano command (cooler) or later using text editor (simpler)
   
5. sudo nano /var/www/html/index.html
   
6. This is a complex bit of html, so just look for something you recognize from the 127.0.0.1 test and change it, like the line "It works!"
   
7. nano is a text editor, so ctrl-o means overwrite, then return to save, and ctrl-x means exit
   
8. If you are using a GUI text editor, it might not let you save.
   

• Next we have to fix the permissions:
  

1. the directory where all of your web pages are stored is /var/www/html
2. we need to "open" the directory so you can play in it, and not have to be sudo to change stuff (for now)
3. to change the permissions on a file, we use chmod, short for "change the mode"
4. permissions are in sets of three: read (4), write (2), execute (1) (to run a program)
5. add them all up to get 7 to do everything
6. so chmod 777 means read this file, write to this file and execute it
7. you might also see these in ls -la as rwx for read, write, execute for owner, group, everyone
8. so 777 would look like rwx, rwx, rwx (look with ls -la)
9. type chmod 755 -R /var/www/html
10. this makes everything in the html directory read and writable to you and anyone can read
    
11. the index.html page is the default that every web browser looks for FIRST
12. you can specify other names in your browser to look around
13. listing the files in a directory is very useful, but also dangerous for hackers

HTML Challenge: Part 1: Making a new web page:

1. cd to the /var/www/html directory and look around (ls -la)
2. Using either nano create a new page:
   
3. sudo nano test.html
   
4. You'll notice this is blank.
   
5. Add the following to your new web page:
   

<html>
<head>
test
</head>
<body>
Wow, this is really easy,I am now a true webmaster!Beware my awesome computer skills!
</body>
</html>

1. remember to overwrite (ctrl-o), return to save,  and exit (ctrl-x)
   
2. Now go to your browser and enter http://127.0.0.1/test.html
   
3. What do you see?
4. Create your own pages in your html folder and test
5. checklist: test.html with your text in it seen from the browser at your web address: http://victim.hpa.edu for example

Migrated from Apple Server Wiki. Original page ID: M9n9_4y