Getting Started with Essential Linux Commands

1. Introduction

While cPanel & WHM automates many administrative tasks, understanding basic Linux commands helps users manage files, troubleshoot issues, and interact with their server more efficiently. This guide covers essential commands and examples to help you get started.

2. Common Linux Commands

To run a command, type it into the CLI and press Enter. Replace FILENAME or LOCATION with your actual paths.

Command	Description	Example
cat FILENAME	Prints the contents of a file.	cat filename.txt
cd LOCATION	Navigate between directories.	cd /usr/local/apache/
chmod permissions FILENAME	Change file permissions.	chmod 755 myfile.txt
chown USER:GROUP FILENAME	Change file ownership.	chown user:group file.txt
cp FILE1 FILE2	Copy a file.	cp original.txt /copies/duplicate.txt
du	Show disk usage.	du
file FILENAME	Detect file type.	file filename
grep string FILENAME	Search for text inside a file.	grep 'example text' file.txt
last	Show recent logins.	last
ln -s file1 file2	Create a symbolic link.	ln -s /path/file1.txt link.txt
ls	List files and directories.	ls
ls -al	View hidden files and details.	ls -al
more FILENAME	View file contents page by page.	more filename.txt
netstat	List network connections.	netstat
pico FILENAME	Edit a file using pico.	pico file.txt
ps	Show running processes.	ps
rm FILENAME	Delete a file.	rm trash.txt
tail -## FILENAME	Show last lines of a file.	tail -20 file.txt
touch FILENAME	Create an empty file.	touch example.txt
vi FILENAME	Edit a file using vi.	vi file.txt
w	Show logged‑in users.	w
wc FILENAME	Count words in a file.	wc file.txt
whereis NAME	Locate installed applications.	whereis perl

3. Running Multiple Commands on One Line

• | — Pipe output from one command to another
• > — Overwrite or create a file
• >> — Append to a file
• < — Use a file as input

Examples

grep User /usr/local/apache/conf/httpd.conf | more

last -a > /root/lastlogins.tmp

mysql --skip-column-names --batch -e 'show processlist' | wc -l

netstat -an | grep :80 | wc -l

tail -10000 /var/log/exim_mainlog | grep 'example\.com' | more

4. Common Configuration Files and Directories

Service	Locations
Exim	/etc/exim.conf /var/log/exim_mainlog /var/log/exim_rejectlog /etc/valiases/ /etc/vfilters/ /home/username/.forward
MySQL	/root/.my.cnf /etc/my.cnf /var/lib/mysql/
ProFTPD	/etc/proftpd.conf /var/log/xferlog /etc/proftpd/
SSH	/etc/ssh/sshd_config
System	/var/log/messages /var/log/dmesg

Conclusion

Learning essential Linux commands helps you manage your server more effectively, troubleshoot issues faster, and understand how cPanel & WHM interacts with the underlying operating system.