Shell Training

Unix Shell

 

Path && Moving

• . means current directory
• .. means parent directory
• ../.. goes to two directories
• '$PATH' means all the environment variables.
  • it will direct to all possible commands that are in $PATHs
• ~ is short for '$HOME'
  • $ >> Environment variable starts with this

 

Useful Commands

• env command: show all possible environment variables
• | pipe oerator: Take output to the input of the next
• grep command: show only that thing
• export [env variable] = ['Something']
  • Setting env variables

vim foo
foo
//This command does not work
chmod u+x foo
foo
// This command works

 

//foo
#!/user/bin/env node
echo 'bar'

 

Shell Configuration

• bash
  • ~/.bashrc
  • ~/.bash_profile
  • ~/.profile
• zsh
  • ~/.zshrc
• fish
• .bashrc

 

. means it's hidden files

ls -l
//l list files
ls -la
//a shows hidden files

 

ln : unlink
# Create Symbolic links
# File short cut
# You can use this to make it to locate in any place
# npm link command

ln -s ~/.local/bin/foo ./foo
ll | grep foo

# You can still use it

htop
# shos a bunch of process that is going now 
# useful when trying to take it and use process id and kill it manually

 

Posix (Portable Operating System Interface)

• Posix is a set of standard operating system interfaces based on the Unix operating system
• Usually accopmlished via the pipe '|' operator

 

Echo ['string'] > foo.txt

• make file

Echo ['string'] >> foo.txt

• append it to file

 

Riggrep (RUST)

• Regular Expressions with Riggrep
• grep 
• rg -L'(const|let) foo
• finding command very fast

 

FZF

• Fuzzy finder
• try to match other things in the file

 

man

• Manual Pages
• search by typing / and include commands
• shift n  goes backward
• shift g >> bottom
• shift gg >> top
• k j >> moving up and down
  • j goes down
  • k goes up
• q || ctrl+C || esc
  • to get out

FONTS = 

• Use in the bash script

&>

• prevents error to stop the shell

figlet

• make words 
• figlet ('hello world')
• fast work typing 
• figlet -I2
  • location for the figlet fonts
  • ls -1 (figlet -I2) | grep .flf
    • shows all figlet fonts

less

• lot of output >> not completing all things >> shows less

 

Directories

• /opt
  • optional
• /bin 
  • Contain binaries such as commands
• /bin

 

System Interrupts

• ctrl + c : kill programs
• ctrl + d : Close to the string and go back >> background
  • fg: bring back the froeground and run it
  • bg: process continues running
  • kill: kill the process
    • kill -9 %2 (kill the second process

 

Fun packages:

- hollywood

 

Use the pipelines