The school computers run Linux. This section covers the minimum you need to get around on the command line.
Warning: Most Linux commands execute immediately without asking for confirmation. A mistyped
rmcommand can permanently delete files with no way to recover them. Read commands carefully before pressing Enter.
The filesystem layout#
Linux organizes all files in a single directory tree rooted at /. There are no drive letters — everything starts from the same root.
| Path | Purpose |
|---|---|
/ |
Root of the filesystem |
/home/firstname.lastname |
Your personal home directory (also written ~) |
/tmp |
Temporary files, cleared on reboot |
/etc |
System configuration files |
/usr/bin |
Programs and commands |
Your home directory /home/firstname.lastname (also written ~) is not where your files are permanently stored. On school computers, the home directory is local to each machine and is wiped on logout. Your persistent storage is an AFS volume (network storage), symlinked to ~/afs.
Anything saved outside of
~/afsis lost when you log out. Always store your work inside~/afs. Because it is network storage, your files are identical on every machine in the school — log in anywhere and find them exactly where you left them.
Essential commands#
Navigation#
| Command | Effect |
|---|---|
pwd |
Print the current directory |
ls |
List files in the current directory |
ls -la |
List with details, including hidden files |
cd dirname |
Enter a directory |
cd .. |
Go up one level |
cd ~ |
Go to your home directory |
Files and directories#
| Command | Effect |
|---|---|
mkdir name |
Create a directory |
touch file |
Create an empty file |
cp src dest |
Copy a file |
mv src dest |
Move or rename a file |
rm file |
Delete a file — no confirmation, no trash |
rm -r dir |
Delete a directory and everything inside it |
cat file |
Print the contents of a file |
less file |
View a file page by page (Q to quit) |
Getting help#
| Command | Effect |
|---|---|
man command |
Open the manual page for a command |
command --help |
Print brief usage information |
AFS#
The AFS (Andrew File System) is the storage space allocated to each student allowing you to store files persistently between different sessions on any computer in the machine hall. Each student has 2GB of storage. Any file stored outside your AFS storage will be lost after a reboot of the computer.
Be careful, this storage space fills up quickly and can cause problems for you if you have reached your quota. Stay vigilant about your usage of the space.