Terminal Cheatsheet

Written by Durgesh Chaudhary on 9/15/2021

Terminal Commands - A Beginner’s Guide

This cheat sheet is intended to be a quick refresher for the main concepts and commands involved in using a terminal. It is not a comprehensive guide but should be enough to get the basics covered.

What is Terminal?
Keyboard Shortcuts
Basic Commands
- man [command]
- whoami
- date
- clear
File System Navigation
File Operations
Other Useful Commands
Conclusion

What is Terminal?

The terminal is a text-based interface for interacting with your computer. It allows you to perform tasks that would be difficult or impossible to do using a graphical user interface. The terminal is also known as the command line, shell, or console.

Why Use Terminal?

Efficiency: Many tasks can be performed more quickly using a terminal than using a graphical interface.
Automation: You can write scripts to automate repetitive tasks.
Flexibility: A terminal gives you more control over your system than a graphical interface.
Remote Access: You can connect to remote servers using a terminal.
Hiring: Many technical jobs require knowledge of a terminal.
Cool Factor: Using a terminal makes you look like a hacker (even if you’re not).

Terminal vs Command Line vs Shell

Terminal: The terminal is the program that allows you to interact with a terminal. It provides a text-based interface for running commands.
Command Line: a terminal is the text-based interface itself. It allows you to type commands and receive output.
Shell: The shell is the program that interprets and executes your commands. There are many different shells available, but the most common one is bash.

Some Keyboard Shortcuts

Ctrl + C: Stop the current command and move to a clear new line.
Up/Down Keys: Cycle through previous commands.
Tab Key: Auto-complete file names and commands. Press twice to see all available options.
Ctrl + L: Clear the terminal screen.
Ctrl + R: Search through command history by typing a search term. It will show the most recent command that matches the search term.
Ctrl + D: Exit the current shell.
q: Quit out of a program that is running in the terminal.

Basic Commands

The following are some of the most commonly used terminal commands:

man [command]

Used to show the manual/documentation for other commands. It shows all the available options, flags, and arguments for the command.
```
man ls
```
In Windows, man is not available. You can use --help instead.
```
ls --help
```
whoami

Prints the username of the current user.
```
whoami # yodkwtf
```
date

Prints the current date and time.
```
date # Fri 10 Dec 2021 10:00:00 AM IST
```
clear

Clears the terminal screen. Works the same as Ctrl + L.
```
clear
```

The following commands are used to navigate around the file system:

pwd

Prints the current working directory.
```
pwd # /home/yodkwtf
```
If you see ~ in the path, it represents the home directory.
ls [dirname]

Lists the files and directories within a directory. By default, it lists the files in the current directory.
```
ls
```
To list files in a specific directory, provide the directory name as an argument.
```
ls /path/to/directory
# ls /Downloads/
```
To list all files (including hidden files), use the -a flag.
```
ls -a
```
To list files with more details (size, permissions, etc.), use the -l flag.
```
ls -l
```
To reverse the order of the list, use the -r flag.
```
ls -r
```
We can also combine flags.
```
ls -ra # hidden files will be at the bottom
```
There are many more flags available. You can check the manual for more information.
cd [dirname]

Changes the current directory to the specified directory.
```
cd /path/to/directory
# cd /Downloads/
```
To go to the home directory, use cd without any arguments.
```
cd
```
Or use cd ~.
```
cd ~
```
To go to the last directory you were in, use cd -.
```
cd -
```
To go up one directory, use cd ...
```
cd ..
```
To go to the root directory of the machine, use cd /.
```
cd /
```
open [file/folder]

To open files, there are different commands based on the operating system.

On MacOS, you can use open.
```
open filename.txt
open Downloads/
```
On Linux, you can use xdg-open.
```
xdg-open filename.txt
xdg-open Downloads/
```
On Windows, you can use start.
```
start filename.txt
start Downloads/
```
We can also open URLs using the same command.
```
open https://yodkwtf.com
```

File Operations

The following commands are used to perform operations on files:

mkdir [dirname]

Creates a new directory with the specified name.
```
mkdir my-project
```

touch [filename]

Creates a new file with the specified name.

touch filename.txt

We can also create multiple files at once.

touch file1.txt file2.txt file3.txt

Create 100 files at once.

touch file-{1..100}.txt
# file-1.txt, file-2.txt, ..., file-100.txt

rm [filename]

Removes a file. Be careful with this command as it permanently deletes the file.
```
rm filename.txt
```
To get a confirmation prompt before deleting each file, use the -i flag.
```
rm -i filename.txt
```
To remove a directory, use the -r flag.
```
rm -r directoryname
```
To remove a non-empty directory without confirmation, use the -rf flag to force it.
```
rm -rf directoryname
```
Note: Be very careful with the rm -rf command. It can delete all the files on your system if used incorrectly.
cp [source] [destination]

Copies a file from the source to the destination.
```
cp file.txt /path/to/destination/
```
If you want to keep the same file name, you can specify the destination directory only otherwise you can specify the new file name.
```
cp file.txt /path/to/destination/
cp file.txt /path/to/destination/newfile.txt
```
To copy a directory, use the -r flag.
```
cp -r directoryname /path/to/destination/
```
mv [source] [destination]

Moves a file from the source to the destination. It can also be used to rename a file.
```
mv file.txt /path/to/destination/
```
To rename a file, specify the new file name as the destination.
```
mv file.txt newfile.txt
```
To move a file and rename it, specify the new path and file name.
```
mv file.txt /path/to/destination/newfile.txt
```
To move a directory, use the -r flag.
```
mv -r directoryname /path/to/destination/
```
cat [filename]

Displays the contents of a file.
```
cat filename.txt
```
To display the contents of multiple files, specify all the file names.
```
cat file1.txt file2.txt file3.txt
```
It can also be used to write to a file.
```
cat > newfile.txt # opens the file in write mode

# type the content and press Ctrl + D to save and exit
```
If the file does not exist, it will create a new file.

If the file already exists, it will overwrite the content. To append to the file, use the >> operator.
```
cat >> filename.txt
```
We can also use > (piping) to do the same things.
```
> newfile.txt
```
We can also use the -n flag to display line numbers.
```
cat -n filename.txt
```
These are just a few of the things cat can do. Check the manual for more information.
less [filename]

Displays the contents of a file one page at a time. Useful for reading large files.
```
less filename.txt
```
To navigate through the file, use the arrow keys or the following keys:
- Space: Move forward one page.
- B: Move backward one page.
- Q: Quit out of the file.
To search for a term, press / and type the search term.

To exit, press Q.
head -n [lines] [filename]

Displays the first few lines of a file. By default, it displays the first 10 lines.
```
head filename.txt
```
You can specify the number of lines to display.
```
head -n 20 filename.txt
```
tail -n [lines] [filename]

Displays the last few lines of a file. By default, it displays the last 10 lines.
```
tail filename.txt
```
You can specify the number of lines to display.
```
tail -n 20 filename.txt
```
To follow the output of a file (like logs), use the -f flag.
```
tail -f filename.txt
```
To display the last 20 lines and follow the output, use the -n flag.
```
tail -n 20 -f filename.txt
```
nano [filename]

Opens a file in the nano text editor.
```
nano filename.txt
```
Nano is a simple text editor that is easy to use. It shows the available commands at the bottom of the screen.

To save the file, press Ctrl + O.

To exit, press Ctrl + X.
echo [text]

Prints text to the terminal.
```
echo "Hello, World!"
```
To write text to a file, use the > operator.
```
echo "Hello, World!" > filename.txt
```
To append to a file, use the >> operator.
```
echo "Hello, World!" >> filename.txt
```

Other Useful Commands

grep [pattern] [filename]

Searches for a pattern in a file.
```
grep "pattern" filename.txt
```
To search for a pattern in all files in a directory, use the -r flag.
```
grep -r "pattern" /path/to/directory/
```
To search for a pattern in a case-insensitive manner, use the -i flag.
```
grep -i "pattern" filename.txt
```
We can use Regexp patterns as well.
```
grep "pattern.*" filename.txt
```
find [directory] -name [filename]

Finds the locations of files and directories based on conditions that you specify.
```
find /path/to/directory/ -name filename.txt
```
To search for a file with a specific pattern, use the * wildcard.
```
find /path/to/directory/ -name "file-0*.txt"
```
To search for a file with a specific pattern and ignore the case, use the -iname flag.
```
find /path/to/directory/ -iname "file-0*.txt"
```
To search for empty files, use the -empty flag.
```
find /path/to/directory/ -empty
```
To find and delete files, use the -delete flag.
```
find /path/to/directory/ -name filename.txt -delete
```
piping

Piping is a way to send the output of one command to another command.
```
ls -l | grep "file"
```
This will list all files in the current directory and then search for the word “file” in the output.

We can also use > to send the output to a file.
```
ls -l > files.txt
```
This will list all files in the current directory and save the output to a file called files.txt.
symlinks (symbolic links)

A symbolic link is a reference to another file or directory. It is similar to a shortcut in Windows.

To create a symbolic link, use the ln -s [srcPath] [symlinkPath] command.
```
ln -s /path/to/file /path/to/symlink
# ln -s ~/Downloads /Desktop/dlds
```
Note that it doesn’t copy or move the file, it just creates a reference to it.

On Windows, you can use mklink to create symbolic links.
```
mklink /path/to/symlink /path/to/file
```
To remove a symbolic link, use the rm command.
```
rm /path/to/symlink
```

tar

The tar command is used to compress and decompress files.

To create a tar archive, use the tar -cvf [archiveName.tar] [files] command.

# create (-c: create, -v: verbose, -f: file)
tar -cvf archive.tar file1.txt file2.txt
tar -cvf archive.tar /path/to/directory/

To see the contents of a tar archive, use the t flag.

# see contents (-t: list, -v: verbose, -f: file)
tar -tvf archive.tar

To extract a tar archive, use the tar -xvf [archiveName.tar] command.

# extract (-x: extract, -v: verbose, -f: file)
tar -xvf archive.tar

To extract a tar archive to a specific directory, use the -C flag.

tar -xvf archive.tar -C /path/to/directory/

To work with a compressed tar archive, use the z flag.

# create (-c: create, -z: compress, -v: verbose, -f: file)
tar -czvf archive.tar.gz file1.txt file2.txt

# extract (-x: extract, -z: compress, -v: verbose, -f: file)
tar -xzvf archive.tar.gz

# see contents (-t: list, -z: compress, -v: verbose, -f: file)
tar -tzvf archive.tar.gz

history

Displays a list of the most recent commands that you have run.
```
history
```
To search through the history, use the grep command.
```
history | grep "touch"
```
To run a command from the history, use ! followed by the command number.
```
!100
```

Conclusion

If you found the cheatsheet helpful please check out more of my work on yodkwtf.com or follow me on twitter. I also run a small youtube channel called Yodkwtf Academy.

Terminal Cheatsheet

Terminal Commands - A Beginner’s Guide

Contents

What is Terminal?

Why Use Terminal?

Terminal vs Command Line vs Shell

Some Keyboard Shortcuts

Basic Commands

man [command]

whoami

date

clear

File System Navigation

pwd

ls [dirname]

cd [dirname]

open [file/folder]

File Operations

mkdir [dirname]

touch [filename]

rm [filename]

cp [source] [destination]

mv [source] [destination]

cat [filename]

less [filename]

head -n [lines] [filename]

tail -n [lines] [filename]

nano [filename]

echo [text]

Other Useful Commands

grep [pattern] [filename]

find [directory] -name [filename]

piping

symlinks (symbolic links)

tar

history

Conclusion