Essential Linux Commands: A Quick Reference Guide
Linux commands are the foundation of effective system administration and everyday tasks. Whether you are a beginner or an experienced user, knowing these fundamental commands is essential. Let us look at some key commands that will help you navigate the Linux environment with ease.
Date and Time Commands:
Display the current date and time.
date
View the calendar
Example: cal
Example: cal 5 2010 (display May 2010 calendar)
File and Directory Management:
Clear the terminal screen.
clear
List directories and files.
ls
Create a new user.
useradd vishal
Set or change a user password.
passwd vishal
Create a user without a password.
passwd -d vishal
Rename a user.
usermod -l n-name o-name
Add a user to a group.
usermod -g group user
Create a user without a duplicate directory.
useradd -n vishal
Delete user with their directory.
userdel -r vishal
Forcefully remove a directory.
rm -rf directory
View group memberships.
groups vishal
View user directory.
vi /etc/passwd
Create a group.
groupadd sales
View group directory.
vi /etc/group
Rename a group.
groupmod -n n-name o-name
How to find files in Linux :
Find the file using file name in Linux.
find /home/user/Documents -name "report.txt"
Find the file using it’s extension in Linux.
find /home/user/Documents -name "*.pdf"
Find the file by size in linux (larger than 10 MB)
find /home/user/Documents -size +10M
System and Configuration:
Switch user.
su vishal
Graphically view any configuration.
system-config-
Create a new tab.
ctrl+shift-t
Switch to the next/previous tab.
ctrl+PgUp/Dn
View files of any command.
/usr/share/doc
Other Useful Commands:
View help about any calendar.
whatis cal
View detailed help about the date command.
date --help
View manual pages about ls.
man ls
View information about history.
info history
Find the path of any directory or command.
which dir
Refers to your home directory.
~ (Tilde)
Time-Saving Tips:
Fully stop a command.
ctrl+c
Stop the terminal.
ctrl+d
Send a program into the background or temporary halt.
ctrl+z
Check programs running in the background.
jobs
Bring a halted program back to run.
fg 1 or 2 or 3
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Conclusion:
These Linux commands provide a foundation for effective system management. Whether you are dealing with files, users, or configurations, mastering these commands will boost your productivity. Stay tuned for more Linux tips and tricks at Linux Guru!