10 Interesting Linux Command Line Tricks and Tips

The command line interface (CLI) is an important feature of Linux operating systems. Although it may seem intimidating at first, it can be a powerful tool for performing various tasks efficiently. In this article, we will discuss some interesting Linux command line tricks and tips that can make your experience with the CLI smoother and more enjoyable.

Navigating the Command Line Interface

The command line interface can be intimidating for beginners, but mastering a few simple commands can make navigating the interface much easier. Here are a few tips to get you started −

Changing Directories

To navigate through the directories on the command line, use the "cd" command. For example, to change to the home directory, type −

cd ~

To change to a directory named "my_directory," type −

cd my_directory

To change to the parent directory, type −

cd ..

Listing Contents

To list the contents of a directory, use the "ls" command. For example, to list the contents of the current directory, type −

ls

To list the contents of a specific directory, type −

ls /path/to/directory

Tab Completion

Tab completion can save you time when typing long file or directory names. To use tab completion, type part of the file or directory name and then press the "Tab" key. The CLI will automatically complete the name for you.

Working with Files and Directories

Working with files and directories on the command line can be faster than using a graphical user interface. Here are some tips to help you manage your files and directories more efficiently −

Copying and Moving Files

To copy a file from one location to another, use the "cp" command. For example, to copy a file named "file.txt" from the current directory to a directory named "my_directory," type −

cp file.txt my_directory/

To move a file from one location to another, use the "mv" command. For example, to move a file named "file.txt" from the current directory to a directory named "my_directory," type −

mv file.txt my_directory/

Creating Directories

To create a new directory, use the "mkdir" command. For example, to create a new directory named "my_directory," type −

mkdir my_directory

Removing Files and Directories

To remove a file, use the "rm" command. For example, to remove a file named "file.txt," type −

rm file.txt

To remove a directory and all its contents, use the "rm" command with the "-r" option. For example, to remove a directory named "my_directory" and all its contents, type −

rm -r my_directory

Finding Files

To find files on the command line, use the "find" command. For example, to find all files with the extension ".txt" in the current directory and its subdirectories, type −

find . -name "*.txt"

Working with Processes

The Linux command line allows you to manage processes running on your system. Here are some tips to help you manage processes more efficiently −

Checking Running Processes

To check the processes currently running on your system, use the "ps" command. For example, to display a list of all processes running on your system, type −

ps -ef

Killing Processes

To kill a process, use the "kill" command. For example, to kill a process with the process ID "1234," type −

kill 1234

Background and Foreground

Sometimes, you may want to run a process in the background so that you can continue using the command line interface. To do this, add an ampersand ("&") at the end of the command. For example, to run a process named "my_process" in the background, type −

my_process &

To bring a background process back to the foreground, use the "fg" command. For example, to bring a process with job ID "1" to the foreground, type −

fg %1

Miscellaneous Tips

Here are some additional tips that may come in handy −

Viewing Command History

To view your command history, use the "history" command. For example, to display a list of your 10 most recent commands, type −

history 10

To repeat a previous command, use the exclamation point ("!"). For example, to repeat the last command you typed, type −

!!

To repeat a specific command from your history, type the command number preceded by an exclamation point. For example, to repeat command number 123, type −

!123

Using Aliases

You can create aliases for commonly used commands to save time. To create an alias, use the "alias" command. For example, to create an alias for the "ls" command so that it always displays file sizes in human-readable format, type −

alias ls='ls -lh'

To make the alias permanent, add it to your .bashrc file.

Using Wildcards

Wildcards can be used to match multiple files or directories with a single command. Here are some examples −

"*" matches any number of characters, including none. For example, to list all files with the extension ".txt," type −

ls *.txt

"?" matches any single character. For example, to list all files with names that begin with "file" and end with a single character, type −

ls file?

Using Pipes

Pipes allow you to take the output of one command and use it as input for another command. For example, to display a list of all files in the current directory sorted by size, type −

ls -l | sort -k5

This will first list all files in the current directory using the "ls" command and then pass the output to the "sort" command, which will sort the files by size.

Using the "grep" Command

The "grep" command allows you to search for specific text in a file or output. For example, to search for the word "error" in a log file named "logfile.txt," type −

grep "error" logfile.txt

This will display all lines in the file that contain the word "error."

Using the "tar" Command

The "tar" command allows you to create and extract compressed archive files. For example, to create a compressed archive file named "my_archive.tar.gz" containing all files in a directory named "my_directory," type −

tar -czvf my_archive.tar.gz my_directory/

To extract the contents of the archive file, type −

tar -xzvf my_archive.tar.gz

Using the "ssh" Command

The "ssh" command allows you to remotely access another computer over a secure connection. For example, to access a remote computer with the IP address "192.168.1.100" using the username "user," type −

ssh user@192.168.1.100

This will prompt you for the password for the specified user on the remote computer.

Using the "curl" Command

The "curl" command allows you to transfer data from or to a server using various protocols, including HTTP, FTP, and SMTP. For example, to download a file from a website, type −

curl -O https://example.com/file.zip

This will download the file and save it in the current directory.

Using the "df" Command

The "df" command displays information about the available disk space on the system's file systems. For example, to display information about the available disk space on the root file system, type −

df /

This will display information about the available disk space, the used space, and the total space on the root file system.

Using the "du" Command

The "du" command allows you to estimate file space usage. It displays the disk space used by files and directories in the current directory or a specified directory. For example, to display the disk space used by all files and directories in the current directory, type −

du

To display the disk space used by a specific directory, type −

du /path/to/directory

Using the "sudo" Command

The "sudo" command allows you to execute commands with administrative privileges. This is useful when you need to perform tasks that require elevated permissions. For example, to install a package using the "apt" package manager with administrative privileges, type −

sudo apt install package_name

This will prompt you for your password and then install the package with administrative privileges.

Conclusion

The command line interface can be a powerful tool for performing various tasks efficiently. With these Linux command line tricks and tips, you can navigate the interface more easily, manage your files and directories more efficiently, and work with processes more effectively. With practice and experience, you can become a command line ninja and impress your colleagues with your skills.