Linux General Commands

cal : show calendar
date : show current date
cal -y 1999 : show 1999 calendar

cd ./Desktop 
cd - : forwarrd

ls ..  
ls /home/milad 
ls -i : ls with inode
ls -l : ls with detail
file permissions - links - user - group - capacity - last access to file
ls -a : all file include hidden file
ls -t : files sorted by last created
ls -r : reverse
ls -R : directory with all path
ls -l -R | ls -latr
 
ln dir1 hardlink1 : error - can not create hardlink for directories - just files
ln file1.txt hardlink1
ln -s dir1 softlink1 : you can create soft link fo directory and files

touch dir1 : change lase access of dir1 - if dir or file doesn't exist create that

mkdir directory1 
mkdir -p directory1/2/3/4
mkdir /home/user/Desktop/tstDir

rmdir directory1 : for empty directory
rmdire Untitled\ directory : \ for spaces
rm * : delete all file in current directory
rm -r directory1 : for directory (empty or not)
rm -f dir1 : force delete
rm -ri dir1 : ask for subdirectory
rm -rv * : delete all file with explain

cp filetst.txt /home/user/Desktop
cp file1.txt file2.txt file3.txt /home/user/Desktop
cp -r test test3 :  copy test with all files and directory to test3
cp -i dir1 dir2 : ask for overwrite files
cp num?? dir1 : copy all file with 5 character
cp [1-3]* dir1 : all file which start with 1-3 and after that anything
cp *[1-9] dir1 : all file which start with anything and end with 1-9
cp [[:upper:]]* dir1 : all file which start with upper text and after that anything | lower | alpha | digit | alphanum
cp [![:upper:]]*[[:digit:]] dir1



mv file1 /home/user/Desktop
mv File_test test : age directory vojod dasht move mikone dar gheyr insoorat  rename mikone
mv -f file1 dir1 : move with overwrite
mv -i file1 dir1 : move with aks for overwrite

file imgFile : description of file

gedit txtFile1 : graphical edit 
nano txtFile1 
less txtFile1
cat txtFile1 : show file content
tac txtFile1 : reverse and show file content
head txtFile1 : default 10 line aval file ro miare
head -n 20 txtFile1 : 20 line az file ro miare
tail txtFile1 : reverse and 10 line of file
tail -20 txtFile1 : az enteha 20 khat ro miare
tail -f txtFile1 : be file negah mikone va age taghiri rokh dad neshoon mide

wc nums.txt | -w : words | -l : lines | -c : capacity
20 20 51 nums.txt
line - word - capacity 


!119 : dastoor 119 az history ro ejra mikone
history 10 : 10 command akhir
ctrl + R : search for command

command types : 
Shell Builtins
Executable Programs : writen by language and compiled
Shell Script
Alias Commands : nam mostaar yek dastoor dige

/bin : all linux commands
/usr/bin : all user commands

type cd : noe dastoor ro mige

locate file1.txt : search file
 
locate file1.txt : age peyda nakard - sudo updatedb - locate file1.txt

whereis ls : address dastoor va tamamie file haye marboote manand manual page

which ls : masire binary file ro neshoon mide

whatis ls : show command type

alias show_works="nano /home/user/Desktop/file1.txt"

alias : show all created alias

unalias show_works : delete alias

cd /home/usr;nano .bashrc : save alias for access all time and add your alias too alias section

file permissions : read - write - execute - owner - group - other

-rw-    rw-    r-- 
owner  group  other 

./test.txt : execute file

chmod +x test.txt : add execute file permission | -r :read | -w :write
chmod -x test.txt : remove execute file permission

octa permisson : 
		owner	group	other
read		  4	  4	  4

write		  2	  2	  2	

execute		  1	  1	  1	

result		  7	  7	  7
	
chmod 400 test.txt : owner just can read file

which ls;sudo chmod 700 /bin/ls : faghat owner mitone command ls ro ejra kone

sudo -i : change user level to root

chattr +i importantFile.txt : even root user cannot edit this file

lsattr : show atribute of files


rename 's/^video_//' *.mp4 : hameye file haei ke ba video_ shoro shodan , video_ ro az esmeshoon haz mikone

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gsettings set org.gnome.shell.extensions.dash-to-dock extend-height false
//flexible dock
gsettings set org.gnome.shell.extensions.dash-to-dock extend-height true
//prevent dock flexible
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steghide embed -cf pic.jpg -ef secret.txt
//add secret to pic.jpg
setghide extract -sf pic.jpg
//extract pic.jpg files
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Error When Try open with root :  Command 'atom' is available in '/snap/bin/atom'
The command could not be located because '/snap/bin' is not included in the PATH environment variable.
atom: command not found.

export PATH="/snap/bin:$PATH"
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Trash Location 
~/root/.local/share/Trash/
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install adapta theme
sudo apt-add-repository ppa:tista/adapta -y
sudo apt update
sudo apt install adapta-gtk-theme
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install bootable windows usb maker program
sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt update
sudo apt install woeusb
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archive file
tar cvf myetc.tar /etc : tar file
tar xvf myetc.tar : untar file
tar cvzf myetc.tar.gz /etc : tar with gzip 
tar xvzf myetc.tar.gz : untar file
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zip file
gzip file1
gzip -d file1.gz
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change display resolution
xrandr : show display properties
sudo xrandr --addmode DP-1 "1360x768" : DP-1 is display name 
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install gimp
sudo add-apt-repository ppa:otto-kesselgulasch/gimp
sudo apt-get update
sudo apt-get install gimp
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Github add ssh key

Check if ssh key exists 
ls -al ~/.ssh : if there is file ssh key are generated]

Generate ssh key
ssh-keygen -t rsa -b 4096 -C "your_email@example.com" 
: press enter to save in default path (~/.ssh) then enter passphrase

Add ssh key to ssh-agent
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_rsa

//then copy ~/.ssh/id_rsa.pub to github accout after that

ssh -T git@github.com
git remote set-url origin git@github.com:username/repo.git

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fix Could not get lock /var/lib/dpkg/lock-open

sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

sudo dpkg --configure -a

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wifi or vpn connect or dissconnect

list all connections : nmcli con

start connection : nmcli con up connectionName

down connection : nmcli con down connectionName

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