Linux Top 10 commands for beginners

Linux is a popular open-source operating system that is widely used for servers, desktop computers, and mobile devices. It is known for its stability, security, and flexibility, and it is the foundation for many other operating systems.

One of the benefits of using Linux is that it provides access to a wide range of powerful command-line tools. These tools allow users to perform a variety of tasks, such as managing files, installing software, and configuring the system.

In this article, we will introduce the top ten commands in Linux that every user should know, along with examples of how to use them.

1. pwd: This command stands for “print working directory” and it displays the path of the current directory.

To use the pwd command, simply open a terminal window and type pwd, then press Enter.

$ pwd
/home/user/documents

The pwd command is useful when you want to know the location of the current directory. It can be especially helpful when you are working with multiple directories and need to keep track of your location in the file system.

2. cd: This command stands for “change directory” and it allows you to navigate the file system.

To use the cd command, type cd followed by the path of the directory you want to navigate to. For example, to navigate to the documents directory, you would type:

$ cd documents
$ cd /home/user/downloads

You can also use the cd command to navigate up one directory level by using the .. notation. For example, to navigate to the parent directory of the current directory, you would type

$ cd ..

The cd command is essential for navigating the file system and accessing different directories and files.

3. ls: This command stands for “list” and it displays the contents of a directory.

To use the ls command, type ls followed by the path of the directory you want to list. For example, to list the contents of the documents directory, you would type:

$ ls documents

You can also use the ls command with various options to customize the output. For example, the -l option displays the contents in a long format, showing additional information such as file permissions and timestamps. The -a option includes hidden files in the listing

$ ls -l documents
total 56
drwxr-xr-x  2 user user  4096 Jan  1  1970 documents
-rw-r--r--  1 user user 12292 Jan  1  1970 report.pdf

$ ls -a documents
.  ..  documents  report.pdf

$ ls
file1.txt file2.txt directory1

The ls command is useful for quickly viewing the contents of a directory and obtaining information about the files and subdirectories it contains.

4. mkdir: This command stands for “make directory” and it allows you to create new directories.

To use the mkdir command, type mkdir followed by the name of the directory you want to create. For example, to create a new directory called project, you would type:

$ mkdir project

For example, to create a new directory called “project” inside the “documents” directory, you can use the following command:

$ mkdir documents/project

You can also use the -p option to create intermediate directories as needed. For example, the following command creates the directories “documents/project/subproject” if they do not already exist:

$ mkdir -p documents/project/subproject

5. cp: This command stands for “copy” and it allows you to copy files and directories.

For example, to copy a file called “report.txt” from the “documents” directory to the “backup” directory, you can use the following command:

$ cp documents/report.txt backup/

6. The rmdir command in Linux is used to remove directories, also known as folders. It can only be used to delete empty directories, as it will not delete directories that contain files or other directories.

To use the rmdir command, you can type rmdir followed by the name of the directory you want to delete. For example:

rmdir -p directory/subdirectory

It is important to use the rmdir command with caution, as it is not possible to recover deleted directories. If you want to delete a directory and all of its contents, you can use the rm command with the -r option, which stands for “recursive.”

rm -r directory_name

This will delete the specified directory and all of its contents, including any subdirectories and files.

7. The chmod command in Linux stands for “change mode” and it is used to change the permissions of a file or directory. Permissions determine which users can access and modify a file or directory.

In Linux, there are three types of permissions: read (r), write (w), and execute (x). These permissions can be set for the owner of the file, the group owner of the file, and all other users.

The chmod command allows you to specify which permissions to set for which users, using either symbolic or numeric notation.

Here is an example of using the chmod command with symbolic notation:

chmod u+x file.txt

This command adds execute permission for the owner (u) of the file file.txt.

Here is an example of using the chmod command with numeric notation:

chmod 755 directory

This command sets read, write, and execute permissions for the owner (7) and read and execute permissions for the group owner and all other users (55) of the directory.

The chmod command can be used to set permissions for multiple files or directories at once by specifying them as arguments. For example:

chmod 644 file1.txt file2.txt file3.txt

This command sets read and write permissions for the owner (6) and read permission for the group owner and all other users (44) for the files file1.txt, file2.txt, and file3.txt. I hope this helps! Let me know if you have any questions.

8. The grep command in Linux is a tool for searching for patterns in text files. It stands for “global regular expression print.” grep searches for a specified pattern in a given input file and prints any lines that match the pattern.

Here is the basic syntax for using grep:

grep pattern input-file

For example, if you have a text file called “log.txt” and you want to search for all lines containing the word “error,” you can use the following command:

grep error log.txt

This will print all lines in “log.txt” that contain the word “error.”

grep can also be used with multiple input files. For example, if you want to search for the word “error” in both “log1.txt” and “log2.txt,” you can use the following command:

grep error log1.txt log2.txt

grep also supports the use of regular expressions, which are special strings that can match complex patterns. For example, if you want to search for lines that contain a three-digit number, you can use the following regular expression

grep '[0-9][0-9][0-9]' input-file

This will print all lines in “input-file” that contain a three-digit number.

9. The find command in Linux is a utility that allows you to search for files and directories based on various criteria, such as name, size, date modified, and permissions. It is commonly used to locate specific files or to search for files that match certain criteria.

Here is an example of how to use the find command:

find / -name "example.txt"

This command will search for a file named “example.txt” starting from the root directory (“/”). The find command will search through all subdirectories and display the path of any files that match the search criteria.

You can also use the find command to search for files based on other criteria, such as size, date modified, and file type. For example:

find / -size +100M

This command will search for files larger than 100 megabytes starting from the root directory.

find / -mtime +30

This command will search for files (as opposed to directories) starting from the root directory.

You can also use the find command in combination with other commands, such as rm to delete matching files or chmod to change the permissions of matching files.

For more information on the find command and its options, you can refer to the manual pages by using the man command:

man find

10. The cat command in Linux is a utility that is used to concatenate (combine) and display the contents of one or more files. It is also frequently used to create new files, view the contents of files, and redirect output from one command to another.

Here is an example of using the cat command to view the contents of a file:

cat file.txt

This will display the contents of the file.txt file on the terminal.

Here is an example of using the cat command to create a new file and add some text to it:

cat > newfile.txt
This is the first line of text in the new file.
This is the second line of text in the new file.

To save the file and exit the cat command, press CTRL+D.

Here is an example of using the cat command to concatenate the contents of two files and display the result on the terminal:

cat file1.txt file2.txt

This will display the contents of file1.txt followed by the contents of file2.txt.

The cat command has many options and arguments that allow you to customize its behavior. For example, the -n option can be used to display line numbers, and the -b option can be used to display line numbers for non-empty lines only. You can use the man cat command to view the manual pages for the cat command and learn about all of its available options.