Einstein - stock prices

Go on the Internet and get today's stock price.
Usage like:

• getprice goog
• getprice msft

We will use this site:

• stockanalysis.com
  • goog (Google/Alphabet)

"View source" and we see that the price is in a section like this:

 <div class="text-4xl font-bold ... ">156.47</div>

The bit in dots "..." seems to vary. Assuming the "text-4xl font-bold" bit is stable, this div can be identified and extracted.

• Note our script will fail in the future if the site format changes. Let us hope it does not change during the lab exam!
• Let us also hope the site's firewall does not block us for the extra traffic during the lab exam. Fingers crossed!

Lab exam

For reasons explained before, in the lab exam we need extension .sh and call it with "./" in front of it.
Also for technical reasons we will call it getprice5.
So the conclusion is that we run it like this:

 ./getprice5.sh (argument) 

---

Getting started

Your program should:

1. Construct the URL based on the command-line argument.
2. Use wget to fetch that URL and output to the command line.
3. Pipe the output to tr to delete all Windows end of line characters. This is important.

Check with Einstein

Stop right now and check it with Einstein to make sure you have some marks.

---

Extract the price

To finish, work through this recipe.

1. Pipe the above output to tr to delete all new line characters (put the entire file onto a single line).

2. Use sed to put a new line before each <div
   and a new line after each </div>
   For clues, see how to put new line before and after HTML tags.

3. grep for "text-4xl font-bold"
   Now you should have just a single line like:

    <div class="text-4xl font-bold ... ">156.47</div>
   

4. Use sed to remove </div>

5. Use sed to remove everything from start of line to >
   You want a regular expression of:

    Start of line - Any sequence of chars - > 

You could in fact extract the price in many different ways.
Any method will do, so long as it extracts the price.

Testing

Run it locally.
Test it locally.
Debug it locally.
When you are happy with it, upload it to Einstein.

Possible issue with changing prices

There is a possible issue with changing prices:

• Einstein gets the real price. Then runs your program to make sure it returns the same.
• The issue is that trading in real-time could in theory change the price in the sub-second interval between Einstein getting the price and Einstein running your program.
• This is probably not why your program is not getting the marks. There is probably another error. But just in case, try running it through Einstein again.

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