# 3.0 Linux Commands

## 3.1 Requirements
- Access to the HPC or a Linux computer

## 3.2 Common commands
- Change password: `passwd`  
- Make directory: `mkdir`  
- Change directory: `cd`  
- Remove file: `rm`  
- Remove directory: `rmdir`  
- Check logged-in users: `who` or `w`  
- Monitor system: `top` (press `1` for per-CPU view, `q` to quit)
- Getting help on various UNIX commands: `man cd` or simply `man`
- Search for text in files: `grep 'search_term' filename`  
- Process and analyze text files: `awk '{print $1}' filename`  
- Count lines, words, and characters in a file: `wc filename`  
- Display the first few lines of a file: `head filename`  
- Display the last few lines of a file: `tail filename`  
- Redirect output to a file: `command > output.txt`  
- Append output to a file: `command >> output.txt`  
- View running processes: `ps aux`  
- Kill a process: `kill process_id`