Unix for Neuroimagers #1: cd, ls, and pwd

Summary

In "Unix for Neuroimagers #1: cd, ls, and pwd," Andrew Jahn introduces some of the most fundamental Unix commands essential for navigating the command line interface. The video focuses on 'pwd' (print working directory), 'cd' (change directory), and 'ls' (list contents), explaining how these commands allow users to view and navigate through directories seamlessly, akin to using a graphical interface like Finder on Mac or File Explorer on Windows. Jahn emphasizes the interchangeable use of the terms 'folder' and 'directory' and provides practical tips on customizing the terminal's appearance and using keyboard shortcuts to enhance efficiency. The video concludes with exercises to reinforce the concepts and sets the stage for more advanced command tutorials in subsequent videos, ensuring a solid foundational understanding for viewers to build upon.

Highlights

• Learn how to navigate Unix directories with pwd, cd, and ls - essential for any aspiring neuroimaging pro! 🧠
• Switch between directories effortlessly, just like point-and-click but with powerful command line magic! ✨
• Customize your terminal till it feels like home - neat tricks for an appealing workspace! 🖥️
• Efficiency hacks such as tab completion and keyboard shortcuts can speed up your command line tasks! ⏩
• Preview of upcoming commands to expand your Unix toolkit - get ready to copy, move, and delete with ease! 🍿

Key Takeaways

• Get to know the basic Unix commands - pwd, cd, and ls - your new buddies for seamless navigation! 🚀
• Folders and directories are just two sides of the same coin in the Unix world - use them interchangeably! 📂
• Spice up your terminal with customizable fonts and colors; it's not just functional but can be fashionable too! 🎨
• Mastering tab completion and shortcuts like 'CTRL + U' will make your command line journey a breeze! 🎯
• Using '~' to go to your home directory and '..' to move up a level will save you time in your path-hopping adventures! 🌟

Overview

In this insightful tutorial, Andrew Jahn guides users through the basics of Unix command line navigation, focusing on three pivotal commands: pwd, cd, and ls. He explains these commands as the key to opening up the powerful and flexible Unix environment, turning the command line into a reliable friend for directory roaming.

Jahn makes learning interactive and engaging, demonstrating how to use the terminal efficiently and personalize its appearance. With handy shortcuts and tips, he shows how to make the terminal experience enjoyable and efficient, debunking the myth that command lines are intimidating.

Finally, the video sets a solid foundation for Unix beginners, providing practical exercises to practice these commands. It also hints at more advanced lessons to come, ensuring that viewers are not only learning commands but understanding the concepts deeply to prepare for more complex operations.

Chapters

• 00:00 - 01:00: Introduction to PWD, CD, and LS This chapter introduces the basic terminal commands PWD, CD, and LS. PWD stands for 'print working directory', CD stands for 'change directory', and LS stands for 'list'. These commands are analogous to navigating through folders on a desktop using a graphical interface, where you click on folders to see their contents.
• 01:00 - 01:30: Using the Terminal and Customizing Appearance The chapter discusses the interchangeability of the terms 'folder' and 'directory' and introduces the terminal as a tool for typing commands and executing tasks. It guides on how to open the terminal via the spotlight search and indicates that the terminal's appearance can vary across different systems. Additionally, it explains how users can customize their terminal's appearance through the preferences, including changes to the font type, font size, and background color.
• 01:30 - 02:00: Basic Terminal Commands: LS and PWD The chapter introduces basic terminal commands, particularly focusing on 'LS' and 'PWD'.
• 02:00 - 02:30: Understanding Directory Paths The chapter 'Understanding Directory Paths' explains the concept of directory hierarchies, starting from the root directory, which is denoted by a forward slash (/). It provides instructions on how to navigate to a folder by using the computer's Finder application, specifically through the 'Go' menu and selecting 'Go to Folder.' Additionally, it introduces the command line operation 'CD,' which stands for 'change directory,' as a method to move to different directories by typing 'CD' followed by the desired directory's name.
• 02:30 - 03:30: Creating Directories and Navigating with CD The chapter explains how to navigate directories using the 'CD' command. It introduces the concept of a relative path, which refers to a directory within the current working directory. An example is provided where the user navigates to the 'desktop' directory using 'CD desktop'. The reader is prompted to type 'LS' to view the contents of the current directory, where they find a folder named 'Andy folder'. The chapter suggests creating another folder as a next step.
• 03:30 - 05:00: Using Shortcuts for Navigation This chapter discusses how to use shortcuts for navigation within a directory. It introduces 'mkdir' as a command to create a new directory and demonstrates creating a directory named 'experiment folder'. The transcript illustrates verifying the creation of directories using the 'ls' command, which lists 'experiment folder' and 'Andy folder' within the desktop directory. Additionally, it covers changing into the 'experiment folder' directory using the 'cd' command.
• 05:00 - 06:00: Advanced Navigation Tips and Tricks The chapter provides advanced navigation tips for using the command line interface. It highlights how to list contents of a directory by typing 'LS', comparing it to double-clicking a folder icon in a graphical interface. For navigation, it mentions that to navigate out of a current directory, you can either type 'CD' followed by the absolute path—which can be cumbersome—or use the shortcut 'CD ..' to move to the parent directory efficiently.
• 06:00 - 06:30: Conclusion: Reviewing Concepts and Previewing Next Video In this chapter, the concept of navigating between directories using terminal commands is reviewed. A single dot signifies the current directory, which is useful for advanced scripting, while double dots represent the directory above in the hierarchy. The text explains that typing 'CD dot' will not change the current directory. Additionally, the creation of two new folders, 'experiment directory' and 'my', is initiated.

Unix for Neuroimagers #1: cd, ls, and pwd Transcription

• 00:00 - 00:30 the first commands we will cover our PWD CD and LS PWD stands for print working directory CD stands for change directory and LS stands for lists as in lists the contents of the current directory this is analogous to pointing and clicking on folder on your desktop and then seeing what's inside note that in these tutorials the words
• 00:30 - 01:00 folder and directory are used interchangeably the terminal is where we type commands and make things happen you can open up a terminal by clicking on the spotlight search icon and typing terminal click on the first result that appears your terminal may not look like mine you can change the appearance by clicking on terminal preferences and then change settings such as font type font size and background color you can
• 01:00 - 01:30 make the size larger or smaller by holding command and then typing the plus sign or the minus sign when you first open up a terminal the default is to start out in your home folder type LS to see what's in here the command returns a list of all the folders and all the files in that directory now type PWD this returns the absolute path to your current directory a list of directories containing other
• 01:30 - 02:00 directories going all the way to your current directory the top of any path or directory hierarchy is called the route symbolized by a forward slash you can see the same thing by opening up finder and clicking go go to folder and typing /if you want to move to a different directory type CD and then the name of the directory for example let's
• 02:00 - 02:30 navigate to the desktop by typing CD desktop this is called a relative path since desktop is a directory within my current working directory in other words if the directory shows up when you type LS you can navigate to it by typing CD and then the name of the directory now type LS and see what's there in this case there is one folder there named Andy folder we can make another
• 02:30 - 03:00 directory by typing mkdir short for make directory and then the name of the directory type mkdir experiment folder and press Enter and then type LS it will return the names experiment folder and Andy folder which are the only things in the desktop directory and you can see a folder icon on your desktop as well now type cd' experiment folder to go
• 03:00 - 03:30 into that directory and type LS to see what's inside this is the same as double-clicking on the experiment folder icon and seeing what's in the finder if you want to get out of this folder from the command line you have two options one is to type CD followed by the absolute path to the desktop directory which is tedious a better option is to use the shortcut CD dot dot in which dot dot represents the parent directory or
• 03:30 - 04:00 the directory immediately above the current directory in the path hierarchy also be aware that a single dot represents the current directory in other words if you typed CD dot you wouldn't go anywhere you would stay exactly where you are this may seem useless but it can be used in more advanced scripting now let's make two more folders one called experiment directory and one called my
• 04:00 - 04:30 folder now type CD exp and then press tab the command line will fill in all of the characters comment both experiment folder and experiment directory in other words the command line knows that you must want something starting with the word experiment but now it can't decide which one to choose if you provide one more letter let's say F and then press tab again then it knows the experiment folder is the only directory with those
• 04:30 - 05:00 characters now remove everything from your command line by holding down ctrl and then pressing U which will save you the trouble of pressing backspace to delete each character let's try one more exercise type CD and then M what do you think happens now if you press tab and Y let's finish with another shortcut command the tilde sign the tilde sign represents the path to your home
• 05:00 - 05:30 directory if you type CD followed by the tilde sign it will take you back to your home directory no matter where you are in the path alternatively if you gate to another directory and then type CD with no filenames or data following it in other words with no arguments you will go back to the home directory what would happen if you typed LS then the tilde Y what about LS tilde
• 05:30 - 06:00 forward slash desktop although we've covered only three commands here we've covered quite a bit of conceptual ground with UNIX review these commands and make sure you understand what they stand for and what they do and then use them for the next five or ten minutes to make sure you feel comfortable with them also review these concepts and try to define them in your own words in the next video we're going to add more commands to our toolbox including commands to copy move
• 06:00 - 06:30 and remove files and directories see you soon