Linux Commandus

echo o/p any text

whoami find user

ls listing ls-a // ls-all hidden files ls -l informative format ls -al mixed ls *.txt show all ended by ".txt" ls a?.txt just one char ls a[0:9] range of char cd change direction

cat show output the files / open the files less show full scren _then =="enter"

pwd where am i "/home/folder"

find -name *.txt find the files find . -name *.txt find the files in the current dir

grep "the word" file. search for a word in file (highlighted)

& run commands in the background

&& two commands

              redirect to another file

             thesame > (overwritten)    

touch create file

mkdir create folder

cp copy

mv move/cut

rm / -R remove (directory)

file find the type of a file

su -l switch users

wget + link download link

head -n + filname print first n lines head -f + filname print last n lines with peiniting the go-on text

ps aux all services

lsof -i open files for internet

netstat -antp network connection

ifconfig information

sort + fliename sort file uniq (sort must) rm dublicate sort a.txt | uniq output of sort is input for uniq

passwd change pass

find / find in all (root)

ctrl + c terminate

ln creat link file (shortcut)

; two command whatever

&& two commands (in case first command run)

|| two commands (in case first command fail)

env info of the environment

which + name where this file is

useradd passwd userdel groupadd passwd groupdel gpasswd -a (username) (groupname)

shadwo / passwd passwords of all

su - switch root su username switch user su username -c command execute one command in username without switch sudo run as root

service start/stop/restart/print status/enable-disable

/ root every thing is here

/bin user binaries (ls.,cp) /sbin sudo commands

/etc sys configs

/usr progrms downloaded

chmod (u,g,o,a) + (rwx) fileName change permission chmod 777 (u=7,g=7,o=7) filename (r=4,write=2,exe=1)

install software 1)apt-get update /\ apt-get update && apt-get upgrade 2)apt-get install (name) -i :install -r :remove

passwd , shadow : stores passwords format sha512

-rwx-rwx-rwx : owner,groups,users read,write,execute

SSH:protocol to connect devices within internet (encrypted)

/etc important directory /var database /root home directory /tmp temporary files

nano [text editor] VIM [advanced editor]

systemctl stop/enaple "service name"

whois + domain name

nslookup -type=a,aaaa (ipv4,ipv6) dig + domain name https://dnsdumpster.com/ https://tryhackme.com/room/shodan

tool -h [help] if there is this tool in system