Discussion 2

FAQs of OS

What’s your point to say this?

We need an app/software, which is called Bash, installed into your computer.

Why we need this?

1. We can use ssh via Bash connect to our lunchbox server.
2. We can use Bash easily run GUIDE.
3. We can use other powerful GNU software. eg. grep, sed, awk

Why do we need to use grep, sed, awk? Can we just use excel, modified data by hand?

1. Yes you can, IN SMALL DATA SET!
2. One question Valid Number Leetcode, if you have 1,000,000 recorders.
3. I may teach in the later semester.

open command prompt;
type `bash`
If you have a problem with bash: 
  if you are using Windows 10:
    see [Windows 10 Installation Guide](https://msdn.microsoft.com/en-us/commandline/wsl/about)
  else if you are using Windows 7:
    try install [UnxUtils](https://sourceforge.net/projects/unxutils/)

Things you can do

Question: I want to execute my guide anywhere, not by copy my guide to anywhere.

We all use hyperlink every day, we like to create a desktop icon in windows or drag the program into your mac Dock, so that we can easily execute the program. Why we can do it easily because we know where is the program. How to let our computer know where is guide or in the future, if you need install some software, how to let our computer know.

Bash has a variable call PATH, which specifying a set of directories where executable programs are located. So that when you type guide into terminal or command line, bash will search that directory, if there is a program call guide, it will execute it, if not, they will say command not found

So that we need to tell our computer “next time you need to search an additional directory where guide is located”

The following steps help you do this (Only do it in the first time), and you can execute guide anywhere on your own computer after.

1. Create the following directory on your computer
   i). ~/local
   ii). ~/local/bin
   
2. Add ~/local/bin into your environment PATH variable

mkdir -p ~/local/bin 
echo 'export PATH=$PATH:~/local/bin' >> .bash_profile
source ~/.bash_profile

mkdir -p flag: no error if existing, make parent directories as needed

You can also use man mkdir in bash to see the details

cd ~/local/bin
wget http://www.stat.wisc.edu/%7Eloh/treeprogs/guide/linux/64bit/Intel/guide.gz
gunzip guide.gz
chmod a+x guide
guide

cd ~/local/bin
curl http://www.stat.wisc.edu/%7Eloh/treeprogs/guide/mac/absoft/guide.gz --output guide.gz
gunzip guide.gz
chmod a+x guide
guide

lunchbox 101

Since it is your friend’s computer, in the beginning, it doesn’t have anything. Even don’t know what’s your homework.

Your friend: Ok, you can use my computer only for homework and computing, you can not play games or watch youtube, promise?
You: Sure, what do you have?
Your friend: I only have a bash terminal…haha, no chrome:P
You: …Ok… Do you have guide?
Your friend: YES!!! Type following in bash

~loh/public/ADDGUIDE

Your friend: You classmates also want to use my computer, so I want to save all your file into one place, OK?
You need to create a directory under /workspace, username is your username to login lunchbox

mkdir -p /workspace/username
cd /workspace/username
guide

Your friend: Let’s try R? DON’T JUST TYPE R!!!!! It will make my computer too slow.

srun R --no-save

You: Hope can I upload my homework?
Your friend: You can install SecureFX, but today let’s use another way to upload your file
Open a new Command Prompt or terminal. You new terminal is not connected to your friend’s computer yet, you can use ls to see everything on your computer not the server.

Your current terminal A already connected to your friend’s computer, then open terminal B.

1. Open a new terminal B, or command prompt
2. Upload your file via terminal B use command scp with flag -r, which means directory, to lunchbox
3. Check your file from terminal A

More details about scp use man scp

bash
cd /mnt/c/Users/WinUserName/Desktop
ls # you should see stat479
scp -r stat479 username@lunchbox.stat.wisc.edu:/workspace/username

cd ~/Desktop
scp -r stat479 username@lunchbox.stat.wisc.edu:/workspace/username