Intro to Linux

Intro to Linux

The shell commands every cluster user needs: moving around, files, permissions, and the habits that keep a shared system happy. Video 6 of 13 in the series Research Computing on Explorer and AICR, built from Northeastern Research Computing's training material. Liam, in for Bear, narrates.

Chapters 0:00 Opening 0:11 The idea 0:31 Terms in this lecture 0:50 I · What Linux Is 1:31 II · Finding Your Way 2:16 III · Making And Moving Files 3:08 IV · Reading Files 3:22 V · Who May Do What 4:27 VI · Editing 4:48 VII · Quick Tips 5:13 Recap 5:44 Your turn

Your turn. Paste this into Claude: I'm new to the Linux terminal on a cluster. Give me a ten-command practice session: make a project folder in my home directory with two subfolders, create a notes file with one line, append a second line, copy it into a subfolder, rename the copy, make the file readable by my group but not by others, and show me the long listing after each step so I can see what changed. Explain each command in one sentence. Then check two things yourself: did every path it wrote start with / or ~? did it warn you before the first rm?

Sources "Introduction to Linux", Northeastern Research Computing, presenter Ghanghoon "Will" Paik; github.com/northeastern-rc-training/Intro-to-Linux-2026. Read 2026-10-06. Questions about the clusters: rchelp@northeastern.edu.

Made with the brutalist.art toolkit: Manim, Remotion and Kokoro, free and local. Narration is synthetic (Liam, in for Bear). This is an independent educational film, not an official Northeastern publication.

▶ The full series playlist — Brutalist https://www.youtube.com/playlist?list=PLG9H-C6rp5RU

What this video covers

• 0:00 — Opening
• 0:11 — The idea
• 0:31 — Terms in this lecture
• 0:50 — I · What Linux Is
• 1:31 — II · Finding Your Way
• 2:16 — III · Making And Moving Files
• 3:08 — IV · Reading Files
• 3:22 — V · Who May Do What
• 4:27 — VI · Editing
• 4:48 — VII · Quick Tips
• 5:13 — Recap
• 5:44 — Your turn

Transcript

A lightly formatted transcript of the video, with timestamps so you can jump to any section on YouTube.

Opening

[0:00] Research Computing on Explorer and AICR. Intro to Linux. The shell commands every cluster user needs. Moving around, files, permissions, and the habits that keep a shared system happy. Salam. This

The idea

[0:11] Is Liam in forbear. First, a correction. The terminal isn't an old way to use a computer. It's the direct way. And on a cluster, it's the main one. The keyboard becomes your only input. This lecture is the basics of the Linux terminal. What Linux is. How to find your way around the file system. How to make, move, and remove files. How to read them. who may do what to them, two editors, and three tips that save you every day. Six terms,

Terms in this lecture

[0:32] The kernel, the core of an operating system, the part that talks to the hardware. A shell, the program that reads what you type and runs it. A directory, a folder, a path, the address of a file written from the root slash or from where you stand. Root, the administrator account that may do anything. And a flag, a dash, and a letter that changes what a command does.

I · What Linux Is

[0:50] Linux is a family of operating systems built on the Linux kernel which Linux Torvalds created in 1991 in the tradition of Unix, the much older system that also shaped MacOSS. It runs on Android phones, on laptops, and on nearly every HPC cluster. It's free and open- source, so anyone can contribute in a huge toolbox comes at no cost, and it's considered secure and robust, which is why servers and clusters run it. Linux has graphical desktops, but underneath is the command line reached through a terminal. The prompt tells you four things. Your username, the host you're on, where you are, and what kind of user you are. A dollar sign means a normal user. A hash means root, the administrator. A normal user can't install system packages. Ask, and you're told you're not in the sudo's file. The

II · Finding Your Way

[1:32] File system is files and directories as on Windows or a Mac. The terminal colors them: blue for directories, green for executables, red for compressed archives, plain for ordinary files. A path is a files address. Absolute from the root starting with a slash. relative from where you stand. One dot is here. Two dots is one level up. Three commands move you around. PWD prints where you are. The tilda is your home. LS lists what's here. Flags change it. D-L for the long listing with permissions, owner, size, and date. Dash for everything, including hidden files whose names start with a dot. Flags combine-l CD changes directory. CD into a folder. The prompt shows you're there. CD dot dot goes one level up. CD alone or CD tilda takes you home from anywhere.

III · Making And Moving Files

[2:16] Making things touch creates an empty file to put text in one redirect. A single greater than overwrites the file. A clean slate. A double one appends to the end. Cat shows the result. And make dire mkdir makes a directory. CP cop is a file. A directory needs capital R recursive to copy what's inside. The original stays. MV moves. And moving a file to a new name is how you rename. RM removes a file. -ash r removes a directory and everything in it. There is no trash can and no undo. On a cluster, a removed file is gone. So read the command twice before you press return. A symbolic link is a shortcut like an alias on a Mac. ln- s then the target then the name you want. Point to target. Call it link name. In a long listing, it starts with L and shows an arrow to where it points. Now cd my data jumps to the deep directory. Move or delete the original and the link breaks. Reading a

IV · Reading Files

[3:09] File. Cat dumps the whole thing into the terminal. Fine for a short one. For a long one, use less. A scrollable viewer. Arrows move a line. Page up and page down a page. Home and end jump to the ends. And Q quits. Escape does not close

V · Who May Do What

[3:22] It. Who may do what? Every file has three audiences. The user who owns it, the group that owns it, and others, everyone else. And three permissions, read, write, and execute, which for directory means entering it. Each permission has a number. Read four, write two, execute one. Here's a real long listing line decoded. The first character is the type. Dash for file. D for a directory. L for a link. Then nine characters in three groups of three. The owner's permissions, the groups, everyone else's. Rwx, the owner can read, write, and execute. Rwash- the group can read and write but not run. R-thers can only read. After that, the link count, the owner, the group, the size in bytes, the modification time, and the name. Changing permissions with chod by symbol who plus or minus which g plus x gives the group execute. U minus X takes it from the owner. Combinations join with commas or by number three digits owner group others each the sum of four two and one 751 is read write execute for the owner read and execute for the group execute only for others and ownership with ch own user colon group then the file-ash capital R for a whole directory. Two editors live in the

VI · Editing

[4:28] Terminal. Nano is the simple one nano and a file name. Its shortcuts are listed along the bottom and the carrot means control. Vim is the powerful one with two modes. In normal mode, you can't type into the file. Press I for insert mode and type. Press escape to get back to normal mode. Type colon WQ to save and quit. Stuck? Escape then colon q exclamation mark quits without saving. Three tips. Tab completes a long

VII · Quick Tips

[4:50] Name. Type the start. Press tab. The shell fills the rest. C stops a running program or throws away a line you've mistyped. And clear wipes the screen. That's the terminal prompt path list. Move. Make. Copy. Remove with care. read permissions and editor and tab. Questions go to the research computing team at rcel@northeastern.edu or to office hours on zoom. Let's recap

Recap

[5:14] With claude. The prompt shows your user host location and whether your route pwdls with flags and cd move you absolute path start from the root. A single dot means here two dots mean up. Touch redirection make dire cp- rmv rm has no undo. Ln-s makes a shortcut. Cat for short files less for long ones. Q quits. read, write, execute for user, group, and others. Changed with chmod by symbol or by number. Nano is simple. Vim is I escape colon wq. Tab completes and control c stops. Your turn. Paste this

Your turn

[5:45] Into claude. I'm new to the Linux terminal on a cluster. Give me a 10 command practice session. Make a project folder in my home directory with two subfolders. Create a notes file with one line. Append a second line. Copy it into a subfolder. Rename the copy. Make the file readable by my group but not by others. and show me the long listing after each step so I can see what changed. Explain each command in one sentence. Then check two things yourself. Did every path it wrote start with a slash or a tilda? And did it warn you before the first RM? Intro to Linux at Nick Bear Brown.