Bash Files and Folders

Most Bash work is moving around folders and working with files. These commands are the ones you will type every day.

Paths

A path tells Bash where a file or folder is.

Path	Meaning
`/`	The root, the top of the whole file system
`~`	Your home folder, for example `/home/ali`
`.`	The current folder
`..`	The parent folder (one level up)
`/home/ali/notes.txt`	An absolute path, starting from `/`
`docs/notes.txt`	A relative path, starting from where you are

Where Am I? pwd and ls

Example

bash

pwd
ls
ls -l
ls -a

pwd prints the current folder.
ls lists files and folders.
ls -l shows a long list with sizes, dates and permissions.
ls -a also shows hidden files, whose names start with a dot.

Options like -l and -a can be joined: ls -la.

Moving Around with cd

Example

bash

cd /tmp
pwd
cd ~
cd ..
cd -

Command	Goes to
`cd folder`	A folder inside the current one
`cd ..`	The parent folder
`cd ~` or just `cd`	Your home folder
`cd -`	The folder you were in before

Creating Files and Folders

Example

bash

mkdir project
cd project
mkdir -p notes/week1
touch todo.txt
echo "Buy notebook" > todo.txt
cat todo.txt
ls

Output

Buy notebook
notes  todo.txt

mkdir makes a folder. -p creates parent folders too, and does not complain if they exist.
touch creates an empty file (or updates the time of an existing one).
cat prints a file's contents.

Copying, Moving and Renaming

Example

bash

cp todo.txt backup.txt
mv backup.txt notes/
mv todo.txt tasks.txt
cp -r notes notes-copy
ls

Output

notes  notes-copy  tasks.txt

Command	What it does
`cp a b`	Copies file `a` to `b`
`cp -r a b`	Copies a folder and everything inside it
`mv a folder/`	Moves `a` into a folder
`mv old new`	Renames a file or folder

Deleting

Example

bash

rm tasks.txt
rm -r notes-copy
rmdir empty-folder

rm deletes files.
rm -r deletes a folder and everything inside it.
rmdir deletes only empty folders.

Be careful: the terminal has no Recycle Bin. A file deleted with rm is gone. Use rm -i to make Bash ask before each deletion, and never run rm -rf unless you are completely sure of the path.

Viewing Files

Command	Use
`cat file`	Show the whole file
`less file`	Scroll through a long file (press `q` to quit)
`head -n 5 file`	Show the first 5 lines
`tail -n 5 file`	Show the last 5 lines
`wc -l file`	Count the lines

Wildcards

The * wildcard matches any text in file names:

Example

bash

ls *.txt
cp *.jpg photos/
rm report-*.pdf

*.txt means "every file ending in .txt". ? matches exactly one character.

Exercise

Which command takes you one folder up?

cd ~cd ..cd /cd .