Class 2B - Introduction to the File System
Contents
Class 2B - Introduction to the File System¶
Announcements¶
Lab 1 will be due Saturday September 18, 2021 at 6 PM
GitHub Classroom and GitHub accounts
My office hours will be 30 minutes after every class on Monday, Wednesday, and Friday 15:00 - 15:30
Lab sessions will be on Zoom, find the link to your Zoom link on Canvas.
File System¶
The file system organizes data on a device as a hierarchy of directories and files (like a tree). Each folder (AKA directory) has a name and can contain any number of files or subdirectories. Each file has a name. The user can change (navigate) directories in the hierarchy.
File System¶
The tree is rooted at, well, the root.
There is only one root of a directory hierarchy. Every item in the tree is either a file or a directory (AKA folder).
You can think of a directory as a container that may contains files and/or other directories.
Files on the other hand hold information (and cannot contain other files or directories) .
If directoryC is contained in directoryP, then directoryC is a child of directoryP and directoryP is said to be the parent to directoryC.
A directory may have many children, but can only have one parent.
Absolute versus Relative Path¶
The root of the file system is the directory “/”
There is only one root of a directory hierarchy.
A path to a new location (from your current location) can be specified as an absolute path from the root (this will work no matter where we are in the file system):
Navigating relative paths¶
.is the short-form for the current directory..signifies the parent directory (akin to pressing Cmnd + ↑ on a Mac)For example, to navigate (i.e. change directories) to the parent directory of the current directory, use the command:
cd ..Note that this command is dependant on your current directory (i.e. the folder you are currently in).
To print the current working directory, type in
pwd
Absolute versus Relative Path Question¶
Consider this directory hierarchy.
The user is currently in the directory
level2The
level1directory contains a file calledtest.txt.
Which of the following statements are TRUE?
A relative path to change to directory 301 is
..Absolute path to
test.txtis/Users/ivrbik/301/level1/test.txtRelative path to
test.txtis ../test.txtRelative path to
test.txtis different if user was currently inlevel3directory.There is only one root of the directory hierarchy.
Activity: Let’s try to re-create that directory and file structure¶
You will need the following commands:
cd: change directorypwd: print working directorymkdir: make directoryls: list directory contentstouch: create an empty file with a specific namecode: edit the file in the VS Code editor
display(Markdown('#### Supplementary video on absolute vs. relative paths'))
IFrame('https://www.youtube-nocookie.com/embed/sqX6hu7oEew',width="100%",height="500px")