Linux Shell and Bash

Bash Tutorial

A brief overview of Bash, on your way to becoming a Linux expert. When a computer boots up, a kernel (MacOS, Windows, Linux) is started. This kernel provides a shell that allows user to interact with a most basic set of commands. Typically, the casual user will not interact with the shell as a Desktop User Interface is started by the computer boot up process. To activate a shell directly, users will run a “terminal” through the Desktop. VS Code provides ability to activate “terminal” while in the IDE.

Prerequisites

Setup bash shell dependency variables for this page.

Hack: Change variables to match your project.

%%script bash

# Dependency Variables, set to match your project directories

cat <<EOF > /tmp/variables.sh
export project_dir=$HOME/vscode  # change vscode to different name to test git clone
export project=\$project_dir/varun  # change teacher to name of project from git clone
export project_repo="https://github.com/varunm532/varun.git"  # change to project of choice
EOF

%%script bash

# Extract saved variables
source /tmp/variables.sh

# Access the variables
echo "Project dir: $project_dir"
echo "Project: $project"
echo "Repo: $project_repo"

Project dir: /home/varunm/vscode
Project: /home/varunm/vscode/varun
Repo: https://github.com/varunm532/varun.git

Setup Project

Pull code from GitHub to your machine. This script will create a project directory and add “project” from GitHub to the vscode directory. There is conditional logic to make sure that clone only happen if it does not (!) exist.

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Using conditional statement to create a project directory and project"

cd ~    # start in home directory

# Conditional block to make a project directory
if [ ! -d $project_dir ]
then 
    echo "Directory $project_dir does not exists... makinng directory $project_dir"
    mkdir -p $project_dir
fi
echo "Directory $project_dir exists." 

# Conditional block to git clone a project from project_repo
if [ ! -d $project ]
then
    echo "Directory $project does not exists... cloning $project_repo"
    cd $project_dir
    git clone $project_repo
    cd ~
fi
echo "Directory $project exists." 

Using conditional statement to create a project directory and project
Directory /home/varunm/vscode exists.
Directory /home/varunm/vscode/varun exists.

Look at files Github project

All computers contain files and directories. The clone brought more files from cloud to your machine. Review the bash shell script observe the commands that show and interact with files and directories.

“ls” lists computer files in Unix and Unix-like operating systems
“cd” offers way to navigate and change working directory
“pwd” print working directory
“echo” used to display line of text/string that are passed as an argument

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Navigate to project, then navigate to area wwhere files were cloned"
cd $project
pwd

echo ""
echo "list top level or root of files with project pulled from github"
ls

Navigate to project, then navigate to area wwhere files were cloned
/home/varunm/vscode/varun

list top level or root of files with project pulled from github
Gemfile
Gemfile.lock
LICENSE
Makefile
README.md
_config.yml
_data
_includes
_layouts
_notebooks
_posts
_site
activate.sh
csa.md
csp.md
csse.md
images
index.md
indexBlogs.md
scripts

Look at file list with hidden and long attributes

Most linux commands have options to enhance behavior

ls reference

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Navigate to project, then navigate to area wwhere files were cloned"
cd $project
pwd

echo ""
echo "list all files in long format"
ls -al   # all files -a (hidden) in -l long listing

Navigate to project, then navigate to area wwhere files were cloned
/home/varunm/vscode/varun

list all files in long format
total 108
drwxr-xr-x 12 varunm varunm 4096 Aug 22 14:20 .
drwxr-xr-x  6 varunm varunm 4096 Aug 18 18:29 ..
drwxr-xr-x  8 varunm varunm 4096 Aug 22 22:20 .git
drwxr-xr-x  3 varunm varunm 4096 Aug 18 18:29 .github
-rw-r--r--  1 varunm varunm  104 Aug 18 18:29 .gitignore
-rw-r--r--  1 varunm varunm  122 Aug 18 18:29 Gemfile
-rw-r--r--  1 varunm varunm 7294 Aug 18 18:31 Gemfile.lock
-rw-r--r--  1 varunm varunm 1081 Aug 18 18:29 LICENSE
-rw-r--r--  1 varunm varunm 3115 Aug 21 13:19 Makefile
-rw-r--r--  1 varunm varunm 5798 Aug 18 18:29 README.md
-rw-r--r--  1 varunm varunm  449 Aug 22 13:24 _config.yml
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 _data
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 _includes
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 _layouts
drwxr-xr-x  2 varunm varunm 4096 Aug 22 14:24 _notebooks
drwxr-xr-x  2 varunm varunm 4096 Aug 22 13:58 _posts
drwxr-xr-x  9 varunm varunm 4096 Aug 23 13:47 _site
-rwxr-xr-x  1 varunm varunm 1291 Aug 18 18:29 activate.sh
-rw-r--r--  1 varunm varunm   92 Aug 18 18:29 csa.md
-rw-r--r--  1 varunm varunm   98 Aug 18 18:29 csp.md
-rw-r--r--  1 varunm varunm  108 Aug 18 18:29 csse.md
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 images
-rw-r--r--  1 varunm varunm 1084 Aug 22 22:22 index.md
-rw-r--r--  1 varunm varunm   53 Aug 18 18:29 indexBlogs.md
drwxr-xr-x  3 varunm varunm 4096 Aug 18 18:29 scripts

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Look for posts"
export posts=$project/_posts  # _posts inside project
cd $posts  # this should exist per fastpages
pwd  # present working directory
ls -l  # list posts

Look for posts
/home/varunm/vscode/varun/_posts
total 52
-rw-r--r-- 1 varunm varunm  1812 Aug 18 18:29 2023-08-15-Tools_Sprint.md
-rw-r--r-- 1 varunm varunm  4397 Aug 18 18:29 2023-08-16-Tools_Equipment.md
-rw-r--r-- 1 varunm varunm 22753 Aug 23 13:57 2023-08-16-linux_shell_IPYNB_2_.md
-rw-r--r-- 1 varunm varunm  3752 Aug 19 17:51 2023-08-17-AP-pseudo-vs-python_IPYNB_2_.md
-rw-r--r-- 1 varunm varunm   468 Aug 18 18:29 2023-08-21-GitHub_Pages.md
-rw-r--r-- 1 varunm varunm  6060 Aug 19 17:51 2023-08-21-VSCode-GitHub_Pages_IPYNB_2_.md

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Look for notebooks"
export notebooks=$project/_notebooks  # _notebooks is inside project
cd $notebooks   # this should exist per fastpages
pwd  # present working directory
ls -l  # list notebooks

Look for notebooks
/home/varunm/vscode/varun/_notebooks
total 56
-rw-r--r-- 1 varunm varunm 33613 Aug 23 13:58 2023-08-16-linux_shell.ipynb
-rw-r--r-- 1 varunm varunm  5415 Aug 18 18:29 2023-08-17-AP-pseudo-vs-python.ipynb
-rw-r--r-- 1 varunm varunm  8616 Aug 19 15:19 2023-08-21-VSCode-GitHub_Pages.ipynb

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Look for images in notebooks, print working directory, list files"
cd $notebooks/images  # this should exist per fastpages
pwd
ls -l

Look for images in notebooks, print working directory, list files
/home/varunm/vscode/varun/_notebooks
total 56
-rw-r--r-- 1 varunm varunm 33613 Aug 23 13:58 2023-08-16-linux_shell.ipynb
-rw-r--r-- 1 varunm varunm  5415 Aug 18 18:29 2023-08-17-AP-pseudo-vs-python.ipynb
-rw-r--r-- 1 varunm varunm  8616 Aug 19 15:19 2023-08-21-VSCode-GitHub_Pages.ipynb


bash: line 6: cd: /images: No such file or directory

Look inside a Markdown File

“cat” reads data from the file and gives its content as output

%%script bash

# Extract saved variables
source /tmp/variables.sh

echo "Navigate to project, then navigate to area wwhere files were cloned"

cd $project
echo "show the contents of README.md"
echo ""

cat README.md  # show contents of file, in this case markdown
echo ""
echo "end of README.md"

Navigate to project, then navigate to area wwhere files were cloned
show the contents of README.md

## Blog site using GitHub Pages and Jekyll
> This site is intended for Students.   This is to record plans, complete hacks, and do work for your learnings.
- This can be customized to support computer science as you work through pathway (JavaScript, Python/Flask, Java/Spring)
- All tangible artifact work is in a _posts or in a _notebooks.  
- Front matter (aka meta data) in ipynb and md files is used to organize information according to week and column in running web site.

## GitHub Pages
All `GitHub Pages` websites are managed on GitHub infrastructure. GitHub uses `Jekyll` to tranform your content into static websites and blogs. Each time we change files in GitHub it initiates a GitHub Action that rebuilds and publishes the site with Jekyll.  
- GitHub Pages is powered by: [Jekyll](https://jekyllrb.com/).
- Publised teacher website: [nighthawkcoders.github.io/teacher](https://nighthawkcoders.github.io/teacher/)

## Preparing a Preview Site 
In all development, it is recommended to test your code before deployment.  The GitHub Pages development process is optimized by testing your development on your local machine, prior to files on GitHub

Development Cycle. For GitHub pages, the tooling described below will create a development cycle  `make-code-save-preview`.  In the development cycle, it is a requirement to preview work locally, prior to doing a VSCode `commit` to git.

Deployment Cycle.  In the deplopyment cycle, `sync-github-action-review`, it is a requirement to complete the development cycle prior to doing a VSCode `sync`.  The sync triggers github repository update.  The action starts the jekyll build to publish the website.  Any step can have errors and will require you to do a review.

### WSL and/or Ubuntu installation requirements
- The result of these step is Ubuntu tools to run preview server.  These procedures were created using [jekyllrb.com](https://jekyllrb.com/docs/installation/ubuntu/)
- Run scripts in scripts directory of teacher repo: setup_ubuntu.sh and activate.sh.  Or, follow commands below.
```bash
## WSL/Ubuntu commands
# sudo apt install, installs packages for Ubuntu
echo "=== Ugrade Packages ==="
sudo apt update
sudo apt upgrade -y
#
echo "=== Install Ruby ==="
sudo apt install -y ruby-full build-essential zlib1g-dev
# 
echo "=== Install Python ==="
sudo apt-get install -y python3 python3-pip python-is-python3
#    
echo "=== Install Jupyter Notebook ==="
sudo apt-get install -y jupyter-notebook

# bash commands, install user requirements.
echo "=== GitHub pages build tools  ==="
export GEM_HOME="$HOME/gems"
export PATH="$HOME/gems/bin:$PATH"
echo '# Install Ruby Gems to ~/gems' >> ~/.bashrc
echo 'export GEM_HOME="$HOME/gems"' >> ~/.bashrc
echo 'export PATH="$HOME/gems/bin:$PATH"' >> ~/.bashrc
echo "=== Gem install starting, thinking... ==="
gem install jekyll bundler
head -30 ./teacher/scripts/activate.sh
echo "=== !!!Start a new Terminal!!! ==="
```

### MacOs installation requirements 
- Ihe result of these step are MacOS tools to run preview server.  These procedures were created using [jekyllrb.com](https://jekyllrb.com/docs/installation/macos/). Run scripts in scripts directory of teacher repo: setup_macos.sh and activate_macos.sh.  Or, follow commands below.
```bash
# MacOS commands
# brew install, installs packages for MacOS
echo "=== Ugrade Packages ==="
brew update
brew upgrade
#
echo "=== Install Ruby ==="
brew install chruby ruby-install xz
ruby-install ruby 3.1.3
#
echo "=== Install Python ==="
brew install python
#    
echo "=== Install Jupyter Notebook ==="
brew install jupyter

# bash commands, install user requirements.
export GEM_HOME="$HOME/gems"
export PATH="$HOME/gems/bin:$PATH"
echo '# Install Ruby Gems to ~/gems' >> ~/.zshrc
echo 'export GEM_HOME="$HOME/gems"' >> ~/.zshrc
echo 'export PATH="$HOME/gems/bin:$PATH"' >> ~/.zshrc
echo "=== Gem install starting, thinking... ==="
gem install jekyll bundler
head -30 ./teacher/scripts/activate.sh
echo "=== !!!Start a new Terminal!!! ==="
```

### Preview
- The result of these step is server running on: http://0.0.0.0:4100/teacher/.  Regeneration messages will run in terminal on any save.  Press the Enter or Return key in the terminal at any time to enter commands.

- Complete installation
```bash
bundle install
```
- Run Server.  This requires running terminal commands `make`, `make stop`, `make clean`, or `make convert` to manage the running server.  Logging of details will appear in terminal.   A `Makefile` has been created in project to support commands and start processes.

    - Start preview server in terminal
    ```bash
    cd ~/vscode/teacher  # my project location, adapt as necessary
    make
    ```

    - Terminal output of shows server address. Cmd or Ctl click http location to open preview server in browser. Example Server address message... 
    ```
    Server address: http://0.0.0.0:4100/teacher/
    ```

    - Save on ipynb or md activiates "regeneration". Refresh browser to see updates. Example terminal message...
    ```
    Regenerating: 1 file(s) changed at 2023-07-31 06:54:32
        _notebooks/2024-01-04-cockpit-setup.ipynb
    ```

    - Terminal message are generated from background processes.  Click return or enter to obtain prompt and use terminal as needed for other tasks.  Alway return to root of project `cd ~/vscode/teacher` for all "make" actions. 
        

    - Stop preview server, but leave constructed files in project for your review.
    ```bash
    make stop
    ```

    - Stop server and "clean" constructed files, best choice when renaming files to eliminate potential duplicates in constructed files.
    ```bash
    make clean
    ```

    - Test notebook conversions, best choice to see if IPYNB conversion is acting up.
    ```bash
    make convert
    ```

end of README.md

Env, Git and GitHub

Env(ironment) is used to capture things like path to Code or Home directory. Git and GitHub is NOT Only used to exchange code between individuals, it is often used to exchange code through servers, in our case deployment for Website. All tools we use have a behind the scenes hav relationship with the system they run on (MacOS, Windows, Linus) or a relationship with servers which they are connected to (ie GitHub). There is an “env” command in bash. There are environment files and setting files (.git/config) for Git. They both use a key/value concept.

“env” show setting for your shell
“git clone” sets up a director of files
“cd $project” allows user to move inside that directory of files
“.git” is a hidden directory that is used by git to establish relationship between machine and the git server on GitHub.

%%script bash

# This command has no dependencies

echo "Show the shell environment variables, key on left of equal value on right"
echo ""

env

Show the shell environment variables, key on left of equal value on right

SHELL=/bin/bash
PYTHONUNBUFFERED=1
WSL2_GUI_APPS_ENABLED=1
APPLICATION_INSIGHTS_NO_DIAGNOSTIC_CHANNEL=1
WSL_DISTRO_NAME=Ubuntu
ELECTRON_RUN_AS_NODE=1
VSCODE_AMD_ENTRYPOINT=vs/workbench/api/node/extensionHostProcess
NAME=Code
PWD=/home/varunm/vscode/varun/_notebooks
LOGNAME=varunm
PYDEVD_IPYTHON_COMPATIBLE_DEBUGGING=1
HOME=/home/varunm
LANG=C.UTF-8
WSL_INTEROP=/run/WSL/578_interop
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:
WAYLAND_DISPLAY=wayland-0
CLICOLOR=1
VSCODE_L10N_BUNDLE_LOCATION=
GEM_HOME=/home/varunm/gems
LESSCLOSE=/usr/bin/lesspipe %s %s
VSCODE_HANDLES_SIGPIPE=true
TERM=xterm-color
LESSOPEN=| /usr/bin/lesspipe %s
USER=varunm
GIT_PAGER=cat
PYTHONIOENCODING=utf-8
DISPLAY=:0
SHLVL=2
PAGER=cat
VSCODE_CWD=/mnt/c/Users/varun/AppData/Local/Programs/Microsoft VS Code
MPLBACKEND=module://matplotlib_inline.backend_inline
XDG_RUNTIME_DIR=/run/user/1000/
WSLENV=ELECTRON_RUN_AS_NODE/w:

VSCODE_WSL_EXT_LOCATION=/mnt/c/Users/varun/.vscode/extensions/ms-vscode-remote.remote-wsl-0.81.0
XDG_DATA_DIRS=/usr/local/share:/usr/share:/var/lib/snapd/desktop
PATH=/bin:/home/varunm/.local/bin:/home/varunm/.vscode-server/bin/6c3e3dba23e8fadc360aed75ce363ba185c49794/bin/remote-cli:/home/varunm/gems/bin:/home/varunm/gems/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/wsl/lib:/mnt/c/WINDOWS/system32:/mnt/c/WINDOWS:/mnt/c/WINDOWS/System32/Wbem:/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/:/mnt/c/WINDOWS/System32/OpenSSH/:/mnt/c/Program Files (x86)/IVI Foundation/VISA/WinNT/Bin:/mnt/c/Program Files (x86)/dotnet/:/mnt/c/Users/varun/AppData/Local/Microsoft/WindowsApps:/mnt/c/Users/varun/Downloads/python/pycharm:/mnt/c/Users/varun/AppData/Local/Programs/Microsoft VS Code/bin:/snap/bin:/home/varunm/.vscode-server/bin/6c3e3dba23e8fadc360aed75ce363ba185c49794/bin/remote-cli:/home/varunm/gems/bin:/home/varunm/gems/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/wsl/lib:/mnt/c/WINDOWS/system32:/mnt/c/WINDOWS:/mnt/c/WINDOWS/System32/Wbem:/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/:/mnt/c/WINDOWS/System32/OpenSSH/:/mnt/c/Program Files (x86)/IVI Foundation/VISA/WinNT/Bin:/mnt/c/Program Files (x86)/dotnet/:/mnt/c/Users/varun/AppData/Local/Microsoft/WindowsApps:/mnt/c/Users/varun/Downloads/python/pycharm:/mnt/c/Users/varun/AppData/Local/Programs/Microsoft VS Code/bin:/snap/bin
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
VSCODE_NLS_CONFIG={"locale":"en","osLocale":"en","availableLanguages":{}}
HOSTTYPE=x86_64
PULSE_SERVER=unix:/mnt/wslg/PulseServer
VSCODE_HANDLES_UNCAUGHT_ERRORS=true
VSCODE_IPC_HOOK_CLI=/run/user/1000/vscode-ipc-f4a55c3a-010b-427c-a98d-7150dcf5c1e3.sock
_=/bin/env

%%script bash

# Extract saved variables
source /tmp/variables.sh

cd $project

echo ""
echo "show the secrets of .git"
cd .git
ls -l

echo ""
echo "look at config file"
cat config

show the secrets of .git
total 56
-rw-r--r--  1 varunm varunm    9 Aug 22 22:20 COMMIT_EDITMSG
-rw-r--r--  1 varunm varunm   94 Aug 23 13:58 FETCH_HEAD
-rw-r--r--  1 varunm varunm   21 Aug 18 18:29 HEAD
-rw-r--r--  1 varunm varunm   41 Aug 22 22:20 ORIG_HEAD
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 branches
-rw-r--r--  1 varunm varunm  259 Aug 18 18:29 config
-rw-r--r--  1 varunm varunm   73 Aug 18 18:29 description
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 hooks
-rw-r--r--  1 varunm varunm 4074 Aug 22 22:20 index
drwxr-xr-x  2 varunm varunm 4096 Aug 18 18:29 info
drwxr-xr-x  3 varunm varunm 4096 Aug 18 18:29 logs
drwxr-xr-x 43 varunm varunm 4096 Aug 23 13:58 objects
-rw-r--r--  1 varunm varunm  112 Aug 18 18:29 packed-refs
drwxr-xr-x  5 varunm varunm 4096 Aug 18 18:29 refs

look at config file
[core]
	repositoryformatversion = 0
	filemode = true
	bare = false
	logallrefupdates = true
[remote "origin"]
	url = https://github.com/varunm532/varun.git
	fetch = +refs/heads/*:refs/remotes/origin/*
[branch "main"]
	remote = origin
	merge = refs/heads/main

Student Request - Make a file in Bash

This example was requested by a student (Jun Lim, CSA). The request was to make jupyer file using bash, I adapted the request to markdown. This type of thought will have great extrapolation to coding and possibilities of using List, Arrays, or APIs to build user interfaces. JavaScript is a language where building HTML is very common.

To get more interesting output from terminal, this will require using something like mdless (https://github.com/ttscoff/mdless). This enables see markdown in rendered format.

On Desktop Install PKG from MacPorts

In Terminal on MacOS

Install ncurses

gem install mdless

Output of the example is much nicer in “jupyter”

%%script bash

# This example has error in VSCode, it run best on Jupyter
cd /tmp

file="sample.md"
if [ -f "$file" ]; then
    rm $file
fi

tee -a $file >/dev/null <<EOF
# Show Generated Markdown
This introductory paragraph and this line and the title above are generated using tee with the standard input (<<) redirection operator.
- This bulleted element is still part of the tee body.
EOF

echo "- This bulleted element and lines below are generated using echo with standard output (>>) redirection operator." >> $file
echo "- The list definition, as is, is using space to seperate lines.  Thus the use of commas and hyphens in output." >> $file
actions=("ls,list-directory" "cd,change-directory" "pwd,present-working-directory" "if-then-fi,test-condition" "env,bash-environment-variables" "cat,view-file-contents" "tee,write-to-output" "echo,display-content-of-string" "echo_text_>\$file,write-content-to-file" "echo_text_>>\$file,append-content-to-file")
for action in ${actions[@]}; do  # for loop is very similar to other language, though [@], semi-colon, do are new
  action=${action//-/ }  # convert dash to space
  action=${action//,/: } # convert comma to colon
  action=${action//_text_/ \"sample text\" } # convert _text_ to sample text, note escape character \ to avoid "" having meaning
  echo "    - ${action//-/ }" >> $file  # echo is redirected to file with >>
done

echo ""
echo "File listing and status"
ls -l $file # list file
wc $file   # show words
mdless $file  # this requires installation, but renders markown from terminal

rm $file  # clean up termporary file

File listing and status
-rw-r--r-- 1 varunm varunm 809 Aug 23 13:59 sample.md
 15 132 809 sample.md

[0m[0;1;47;90mShow Generated Markdown [0;2;30;47m========================================================[0m

This introductory paragraph and this line and the title above are generated
using tee with the standard input (<<) redirection operator.
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[0;1;91m- [0;1;91m[0;97mThis [0;97mbulleted [0;97melement [0;97mand [0;97mlines [0;97mbelow [0;97mare [0;97mgenerated [0;97musing [0;97mecho [0;97mwith [0;97mstandard
[0;97moutput [0;97m(>>) [0;97mredirection [0;97moperator.
[0;1;91m- [0;1;91m[0;97mThe [0;97mlist [0;97mdefinition, [0;97mas [0;97mis, [0;97mis [0;97musing [0;97mspace [0;97mto [0;97mseperate [0;97mlines. [0;97mThus [0;97mthe [0;97muse [0;97mof
[0;97mcommas [0;97mand [0;97mhyphens [0;97min [0;97moutput.
      [0;1;91m- [0;1;91m[0;97mls: [0;97mlist [0;97mdirectory
      [0;1;91m- [0;1;91m[0;97mcd: [0;97mchange [0;97mdirectory
      [0;1;91m- [0;1;91m[0;97mpwd: [0;97mpresent [0;97mworking [0;97mdirectory
      [0;1;91m- [0;1;91m[0;97mif [0;97mthen [0;97mfi: [0;97mtest [0;97mcondition
      [0;1;91m- [0;1;91m[0;97menv: [0;97mbash [0;97menvironment [0;97mvariables
      [0;1;91m- [0;1;91m[0;97mcat: [0;97mview [0;97mfile [0;97mcontents
      [0;1;91m- [0;1;91m[0;97mtee: [0;97mwrite [0;97mto [0;97moutput
      [0;1;91m- [0;1;91m[0;97mecho: [0;97mdisplay [0;97mcontent [0;97mof [0;97mstring
      [0;1;91m- [0;1;91m[0;97mecho [0;97m"sample [0;97mtext" [0;97m>$file: [0;97mwrite [0;97mcontent [0;97mto [0;97mfile
      [0;1;91m- [0;1;91m[0;97mecho [0;97m"sample [0;97mtext" [0;97m>>$file: [0;97mappend [0;97mcontent [0;97mto [0;97mfile

[0m

Hack Preparation.

Review Tool Setup Procedures and think about some thing you could verify through a Shell notebook.

Come up with your own student view of this procedure to show your tools are installed.

Name and create notes on some Linux commands you will use frequently.

Is there anything we use to verify tools we install? Review versions checks.

Is there anything we could verify with Anaconda? or WSL?

How would you update a repository? Could you do that in script above?

Linux Shell and Bash • 49 min read

Description

Bash Tutorial

Prerequisites

Setup Project

Look at files Github project

Look at file list with hidden and long attributes

Look inside a Markdown File

Env, Git and GitHub

Student Request - Make a file in Bash

Hack Preparation.