Filesystem

• Directories -- analogous to folders in Windows or OS X
• Subdirectories -- analogous to subfolders Windows or OS X
• Highest directory is "/"

Filesystem Commands

• ls: lists the contents of a directory
• cd [directory_path]: “goes into” a directory
• mkdir [dir_name]: makes a new directory
• rmdir [dir_name]: removes a directory

• touch [file_name]: creates an empty file

It's Your Turn 1

Goal: to set up a directory with two files

• Make a directory called "cs21"
• Go into "cs21"
• Create a new dir called "hw01"
• Create a new dir called "hw02"
• List the contents of "cs21"

Time Savers

cd takes you back to your home directory (back to /home/username)
cd .. takes you one directory up
cd - takes you back to the directory you were just at
pwd prints the working directory; tells you where you are

Tilda:
~ is a shorthand for home directories
cd ~ is equivalent to cd /home/your_home_dir
cd ~jk is equivalent to cd /home/jk

Tab completion: hitting the TAB key will complete the name of the file or directory for you; tabbing twice will produce a list of possible filenames if more than one exists.

It's Your Turn 2

Goal: to explore the cd command; to go into a specific folder

In "cs21"

• Print the working directory
• In "cs21", make a new directory called "usingunix"
• Go into "usingunix"
• Type cd
• Where do you end up? (Print the working directory)
• Get to "usingunix" again
• Type cd ..
• Where do you end up? (Print the working directory)
• List the contents of the /scratch/usingunix directory in the long format.

Filesystem Commands

mv [file1] [file2] : renames a file
cp [file1] [file2] : copy the contents of one file to another file (copy)
rm [file] : remove a file

It's Your Turn 3

• In your "cs21" dir, rename "usingunix" to be "UsingUnix"
• copy the files from /scratch/usingunix into your UsingUnix dir
• List the contents of the directory
• view the contents of a file with less filename

Smart Programming: make backup versions of your work with cp