Intoduction

The command line is an incredibly powerful tool for Linux users, offering a fast and efficient way to perform tasks, automate processes, and manage the system. Here are some essential Linux command line tricks categorized to enhance your productivity.

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File and Directory Management

Command	Description
ls -lah	List files in a directory with detailed information, including hidden files.
cd -	Switch back to the previous directory you were in.
find / -type f -size +100M	List files larger than 100MB to help free up disk space.
du -sh *	Show the size of all files and folders in the current directory.
mkdir new_directory	Create a new directory.
rm -rf directory_name	Remove a directory and all its contents.
touch newfile.txt	Create a new empty file.
mv oldname.txt newname.txt	Rename or move a file.
cp -r source_directory destination_directory	Copy directories and their contents recursively.
tar -cvf archive.tar directory/	Create a .tar archive from a directory.
tar -xvf archive.tar.gz	Extract the contents of a .tar.gz archive.

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Process and System Monitoring

Command	Description
top	Display real-time CPU and memory usage.
htop	An enhanced version of top with a more user-friendly interface.
ps aux	Display all running processes.
kill -9 <PID>	Kill an unresponsive process by its Process ID (PID).
pkill process_name	Kill a process by its name instead of PID.
uptime	Show how long the system has been running.
free -m	Check current memory usage in megabytes.
df -h	Check available disk space in a human-readable format.
journalctl -xe	View system logs for debugging errors.
systemctl status service_name	Check the status of a system service.
systemctl restart service_name	Restart a system service.

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User and Permission Management

Command	Description
whoami	Show the current logged-in user.
passwd	Change the user password.
chmod 755 script.sh	Change file permissions to make a script executable.
chown user:group filename	Change ownership of a file or directory.
adduser username	Add a new user to the system.
deluser username	Remove a user from the system.

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Networking and Connectivity

Command	Description
ping google.com	Send a test signal to Google to check if the internet connection is working.
traceroute google.com	Trace the path packets take to reach Google.
netstat -tulnp	Show active network connections and listening ports.
iptables -L -v -n	List firewall rules.
hostname -I	Display the IP address of the machine.
wget URL	Download a file from the internet.
curl -O URL	Download a file using curl.
scp file.txt user@remote:/destination/path	Securely transfer files between computers using SSH.
rsync -avz source/ destination/	Synchronize files and directories efficiently.

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Text Processing and Search

Command	Description
grep "word" filename.txt	Search for a specific word inside a text file.
awk '{print $1, $3}' filename.txt	Extract specific columns from a text file.
sed 's/old-text/new-text/g' filename.txt	Replace all occurrences of old-text with new-text.
cat filename.txt	Display the contents of a file.
tail -f /var/log/syslog	Continuously monitor system logs for updates.

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Productivity Boosters

Command	Description
ctrl + r	Search for a specific command in history.
alias ll='ls -lah'	Create a shortcut for frequently used commands.
history | grep command	Search command history for a specific command.
!!	Re-run the last executed command.
python3 -m http.server 8000	Start a temporary web server in the current directory on port 8000.

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Conclusion

Mastering these Linux command-line tricks can greatly enhance your efficiency and control over your system. Whether you’re a beginner or an advanced user, these categorized commands will help streamline your workflow. Try them out and take your Linux skills to the next level!