Basic Linux commands

June 9, 2025 · 614 words · 3 min read

Contents

The basic Linux commands for beginners, including file management, system information, and process control.

Linux is a powerful and versatile operating system widely used in servers, development environments, and cloud systems. Whether you’re a beginner or looking to refresh your skills, mastering basic Linux commands is essential for navigating the file system, managing processes, checking system information, and handling networks or files efficiently. This cheat sheet provides a quick reference to commonly used Linux commands, organized by category for easy access.

Here’s a list of all the basic Linux commands from the image you provided, grouped by category:

FILES & NAVIGATING

ls – directory listing
ls -l – formatted listing
ls -la – formatted listing including hidden files
cd dir – change directory to dir
cd .. – change to parent directory
cd ./dir – change to dir in parent directory
cd ~ – change to home directory
pwd – show current directory
mkdir dir – create a directory
rm file – delete file
rm -f dir – force remove file
rm -rf dir – delete directory dir
rm -r dir – remove directory dir
rm -rf / – launch some nuclear bombs targeting your system
cp file1 file2 – copy file1 to file2
mv file1 file2 – rename file1 to file2
mv file1 dir/file2 – move file1 to dir as file2
touch file – create or update file
cat file – output contents of file
cat > file – write standard input into file
cat >> file – append standard input into file
tail -f file – output contents of file as it grows

SYSTEM INFO

date – show current date/time
uptime – show uptime
whoami – who you’re logged in as
w – display who is online
cat /proc/cpuinfo – display CPU info
cat /proc/meminfo – memory info
free – show memory and swap usage
du – show directory space usage
du -sh – displays readable sizes in GB
df – show disk usage
uname -a – show kernel config

NETWORKING

ping host – ping host
whois domain – get whois for domain
dig domain – get DNS for domain
dig -x host – reverse lookup host
wget file – download file
wget -c file – continue stopped download
wget -r url – recursively download files from URL
curl url – outputs the webpage from URL
curl -o meh1.html url – writes the page to meh1.html
ssh user@host – connect to host as user
ssh -p port user@host – connect to host on port
ssh -D user@host – connect & use bind port

COMPRESSING

tar cf file.tar files – tar files into file.tar
tar xf file.tar – untar into current directory
tar tf file.tar – show contents of archive

tar options:

c – create archive
t – table of contents
x – extract
z – use zip/gzip
f – specify filename
j – bzip2 compression
w – ask for confirmation
k – do not overwrite
T – files from file
v – verbose

PERMISSIONS

chmod octal file – change permissions of file

Permission values:

4 – read (r)
2 – write (w)
1 – execute (x)

Order:

owner/group/world

Examples:

chmod 777 – rwx for everyone
chmod 755 – rw for owner, rx for group/world

PROCESSES

ps – display currently active processes
ps aux – detailed outputs
kill pid – kill process with process id (pid)
killall proc – kill all processes named proc

SOME OTHERS

grep pattern files – search in files for pattern
grep -r pattern dir – search for pattern recursively in dir
locate file – find all instances of file
whereis app – show possible locations of app
man command – show manual page for command