Linux

Linux is an immensely powerful operating system famous for flexibility and tuns of control through its command-line interface or CLI. This article will group essential Linux commands and provide some examples to help you better understand and use Linux commands.

1. File and Directory Management

Command	Description	Example

pwd

Prints the current working directory.

$ pwd → /home/user/Documents

ls

Lists files and directories.

$ ls → file1.txt file2.txt folder1

cd

Changes the current directory.

$ cd folder1 → Navigates into folder1.

mkdir

Creates a new directory.

$ mkdir new_folder → Creates a directory named new_folder.

touch

Creates an empty file.

$ touch new_file.txt → Creates a file named new_file.txt.

cp

Copies files or directories.

$ cp file1.txt /backup/ → Copies file1.txt to /backup/.

mv

Moves or renames files.

$ mv file1.txt renamed_file.txt → Renames the file.

rm

Deletes files or directories.

$ rm file1.txt → Deletes file1.txt.

find

Searches for files/directories.

$ find /home -name "*.txt" → Finds all .txt files in /home.

tree

Displays directories in tree form.

$ tree → Displays a tree-like structure of direct

2. File Viewing and Editing

Command	Description	Example
`cat`	Displays file content.	`$ cat file1.txt` → Outputs the content of `file1.txt`.
`more`	Views file content one screen at a time.	`$ more largefile.txt` → Displays `largefile.txt` page by page.
`less`	Similar to `more` but allows backward scrolling.	`$ less largefile.txt` → Lets you scroll back and forth.
`nano`	Edits files with a simple text editor.	`$ nano notes.txt` → Opens `notes.txt` in the Nano editor.
`vim`	Advanced text editor.	`$ vim` `script.sh` → Opens `script.sh` for editing in Vim.
`head`	Displays the first lines of a file.	`$ head -n 5 file1.txt` → Shows the first 5 lines.
`tail`	Displays the last lines of a file.	`$ tail -n 10 file1.txt` → Shows the last 10 lines.

3. User Management

Command	Description	Example
`whoami`	Displays the current user.	`$ whoami` → `john_doe`
`id`	Shows user ID and group ID.	`$ id` → `uid=1000(john_doe) gid=1000(john_doe)`
`adduser`	Adds a new user.	`$ sudo adduser alice` → Creates a new user named `alice`.
`passwd`	Changes a user's password.	`$ passwd` → Prompts to change the password.
`chmod`	Changes file permissions.	`$ chmod 755` `script.sh` → Grants execute permissions.
`chown`	Changes file ownership.	`$ sudo chown alice:alice file1.txt` → Changes ownership to user `alice`.

4. Process Management

Command	Description	Example
`ps`	Displays running processes.	`$ ps` → Lists active processes for the current user.
`top`	Shows real-time system usage.	`$ top` → Displays running processes, CPU, and memory usage.
`kill`	Terminates a process by PID.	`$ kill 1234` → Stops the process with PID `1234`.
`jobs`	Lists active jobs.	`$ jobs` → `[1]+ Running sleep 100 &`
`bg`	Resumes a job in the background.	`$ bg %1` → Resumes job 1 in the background.
`fg`	Resumes a job in the foreground.	`$ fg %1` → Brings job 1 to the foreground.

5. Networking Commands

Command	Description	Example
`ping`	Tests connectivity to a host.	`$ ping` `google.com` → Sends ICMP packets to `google.com`.
`curl`	Transfers data from/to a server.	`$ curl -O` `https://example.com/file.zip` → Downloads `file.zip`.
`wget`	Downloads files from the web.	`$ wget` `https://example.com/file.zip` → Downloads `file.zip`.
`ssh`	Connects to a remote server.	`$ ssh user@192.168.1.1` → Opens an SSH session.

6. Disk Management

Command	Description	Example
`df`	Displays disk space usage.	`$ df -h` → Shows disk usage in a human-readable format.
`du`	Displays directory size.	`$ du -sh /var/log` → Shows the size of `/var/log`.
`lsblk`	Lists block devices.	`$ lsblk` → Displays attached drives and partitions.

7. Archiving and Compression

Command	Description	Example
`tar`	Archives files.	`$ tar -cvf archive.tar folder/` → Creates `archive.tar` from `folder/`.
`gzip`	Compresses files.	`$ gzip file1.txt` → Creates `file1.txt.gz`.
`gunzip`	Extracts `.gz` files.	`$ gunzip file1.txt.gz` → Restores `file1.txt`.

8. Advanced Commands

Command	Description	Example
`grep`	Searches for text in files.	`$ grep "error" logs.txt` → Finds "error" in `logs.txt`.
`awk`	Processes text patterns.	`$ awk '{print $1}' file.txt` → Displays the first column.
`sed`	Edits text streams.	`$ sed 's/old/new/g' file.txt` → Replaces "old" with "new".

Conclusion

Using examples, the participants will master the necessary commands and gain greater confidence while dealing with Linux systems. Would you like to know more about an extended use of a definite command? Let us know in the comments!

Mastering Linux Commands: A Beginner-to-Advanced Guide