Basic Command for Beginner How to Use Linux

Basic Command for Beginner How to Use Linux. This Linux guide will help you understand useful Linux command for Linux terminal. This is little important to speed up your Linux task beside of using GUI through Linux application. To make things even easier, we have color coded this chart: Commands are purple, variables such as command options, flags and user defined files or directories are blue and you will most likely substitute these with your own.

Basic Command for Beginner How to Use Linux

Basic Command for Beginner How to Use Linux

Command	Description
man command	Often referred to as the ‘man page’, most commands have a users manual. These manuals list available options, proper usage and general information. We strongly suggest you utilize man and learn more about the command before using it.

Linux Command for Navigation & Directories

Command	Description
ls	Lists the contents of the directory.
pwd	Display the name of the directory you’re currently in.
cd ..	Changes your directory down one level.
cd dir	Changes to the directory named ‘dir’.
cd /	Changes to the root directory. You may also states directories explicitly. Eg: cd /home/user
cd ~	Changes to your home directory.
cd ~-	Changes to the last directory you were in.

Linux Command for File Management

Command	Description
cp file1 file2	Copies the file named ‘file1’ to another file called ‘file2’. Leaving the original ‘file1’ intact.
mv file1 file2	Moves (renames) the file ‘file1’ to ‘file2’.
mkdir dir	Creates a directory named ‘dir’.
rm file	Removes the file ‘file’.
rm -f dir	Removes the directory ‘dir’ and anything in it.
rmdir foo	Removes the directory ‘foo’. This only works if the directory is empty.
cat somefile	Scroll the contents of the file ‘somefile’ on your terminal all at once.
cat somefile	Displays the contents of ‘somefile’ on your screen, and lets you scroll through it slowly.
tail somefile	Displays the last 10 lines of somefile.

Linux Command for Processes and Programs

Command	Description
ps -aux	Shows every process that is running on your system and associated process ID.
kill -9 1234	Stops the program process ID ‘1234’ (from ps aux).

Linux Command for Searching

Command	Description
whereis something	Searches common locations for the program ‘something’.
whatis something	Use this command if you are unsure what a program does, it should spit out a short synopsis.
grep -R something	Searches for the word ‘something’ in your current directory.
find / -name something	Searches the / dir for ‘something’.

Linux Command for The System

Command	Description
date	Display the current date and time. To adjust system date use: date -s “Thurs Aug 27 14:38:00 EST 2000”
hostname	Display the system hostname.
uptime	Gives a one line display of time, how long the system has been running, users logged in and load averages.
top	A listing of running processes sorted by CPU usage in real time.
free -m	Information on system memory (in megabytes).
df -h	Display information on disks and file systems (in human-readable format).
cat /proc/version	Display information on your version of Linux.
cat /proc/cpuinfo	Display CPU information on the system.
cat /proc/filesystems	Display information on the file system types in use.
uname -a	Display information on the kernel version.
shutdown -h now	Halts (-h) the system, shutting it down soon as you press enter. You can also specify a time, i.e shutdown -h +15, this means the system will halt in 15 mins.
shutdown -r now	Reboots (-r) the system, rebooting it soon as you press enter. You can also specify a time, i.e shutdown -r +15, this means the system will reboot in 15 minutes.

Linux Command for Users and Groups

Command	Description
whoami	Displays who you are logged in as.
who	Display a list of users currently logged into the system.
last -10	Display a list of the last 10 users logged into the sytem, alternatively you can specify a username.
useradd	To add a new user on your system. See man page for options.
usermod	Used to modify a user account. See man page for options.
passwd	Allows you to change an already existing user account password.
userdel -r username	To remove a user from your system, along with all files owed by the user.
su –	Become superuser (root). Note: Some version of Linux use sudo.

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