OPERATING SYSTEM COMMANDS

pwd

prints your current working directory.

cd

changes your directory.

ls

lists the contents of a directory.

mkdir

creates new directories.

rmdir

deletes an empty directory.

touch

creates and updates files.

cp

copies files and directories.

mv

moves or renames files and directories.

rm

removes files and directories.

ln

creates symbolic links.

cat

shows the content of a file.

less

shows the content of a file interactively.

head

displays the beginning of a file.

tail

displays the last part of a file.

echo

prints text to the terminal or to files.

truncate

shrinks or extends the size of a file.

grep

searches for patterns in text.

find

searches for files and directories.

awk

extracts and manipulates data from files.

sed

edits text streams for finding and replacing.

tr

translates or deletes characters.

cut

removes sections from lines of a file.

wc

counts lines, words, and bytes in a file.

ps

shows a snapshot of running processes.

pstree

displays the hierarchical structure of processes.

top

provides a real time overview of running processes.

kill

sends signals to terminate a process.

killall

terminates processes by their program name.

jobs

lists background tasks running in the terminal.

bg

continues the execution of a paused background task.

fg

brings a background task to the foreground.

free

displays total, used, and free memory.

systemctl

manages systemd services and daemons.

crontab

manages scheduled automated tasks.

date

displays or sets the system date and time.

cal

shows a calendar.

timedatectl

queries or changes date and time settings.

hostnamectl

displays the operating system name and architecture.

chmod

changes file and directory permissions.

chown

changes the owner and group of a file.

adduser

creates a new user.

userdel

deletes an existing user.

passwd

changes a user's password.

groupadd

creates a new user group.

groupmod

modifies existing user groups.

groupdel

deletes a user group.

whoami

displays the current logged in user.

id

shows user and group information.

su

switches to another user or the root superuser.

sudo

executes a command with administrator privileges.

visudo

safely edits the file that grants sudo privileges.

ip a

displays IP addresses and network interface information.

ping

tests connectivity to another network node.

traceroute

traces the path packets take to a destination.

arp

shows the table mapping IP addresses to MAC addresses.

tar

packs and unpacks file archives.

gzip

compresses files into the .gz format.

gunzip

decompresses .gz files.

zip

compresses files into the .zip format.

unzip

extracts .zip files.

apt

manages software packages in Ubuntu.