Computer-Science-Workshop

Bash scripts

Add a #!/bin/bash at the top to specify the interpreter (bash, zsh etc.)

Use # for single-line comments.

Variables

• Assign with = (no spaces): variable_name=value
• Access with $variable_name

Control Structures

If-Else

Control Structures - If-Else: if [ condition ]; then # commands elif [ condition ]; then # commands else # commands fi

Operators

• && for logical AND
• || for logical OR
• == for EQUALS
• != for numerical comparison
• [ "$str1" != "$str2" ] for string comparisons

For Loop

  for var in list; do
      # commands
  done

While Loop while [ condition ]; do Commands done

Arrays Declare: array_name=(value1 value2 value3) Access: ${array_name[index]}

Try it out

1. Create a fork of: https://github.com/kthcloud/Computer-Science-Workshop/
2. Clone the repo to your local computer
3. Go to the Day2/Shell-Part-2 folder
4. Make the example_script.sh executable and try to run it
5. Write a second bash script that:
   • Counts to 40
   • Generates a random number for each index using: random_number=$((RANDOM))
   • If both the random number and the index are even:
     • Run example_script.sh
   • Otherwise:
     • Print the product of the numbers to the console

   Tip: Start by making the loop and running the script for every iteration.

Tmux

Tmux (Terminal Multiplexer) is a powerful tool that allows you to create multiple terminal sessions within a single window. It lets you split your terminal into panes, create multiple windows, and most importantly, keep your sessions running even after disconnecting. This is especially useful for remote work and long-running processes.

Basic Session Commands

• Create new session: tmux new -s <name>
• Attach to session: tmux a -t <name>
• Detach from session: tmux detach
• List all sessions: tmux ls
• Delete a session: tmux kill-session -t <name>

Note: -a stands for attach, -t stands for target

Terminal Split Commands (Using Our Configuration)

• Create new vertical split: Ctrl + A + |
• Create new horizontal split: Ctrl + A + -
• Remove a split: Select the split and press Ctrl + B + D

This site is open source. Improve this page.