List of contents

1. General commands
2. Bash/Terminal related commands
3. Permission related commands
4. APT(Package manager) commands
5. Tar commands
6. Grep commands

General commands

➤ Watch present directory

pwd

➤ Watch the files and folders in present directory

ls

➤ Navigate directory to back

cd ..

➤ Navigate directory to a folder

cd <folder name>

➤ Create directory

mkdir <directory name>

➤ Create file

touch <filename>

➤ Remove/Delete empty directory

rmdir <directory name> rm -d <directory name>

➤ Remove/Delete directory that contains data

rm <directory name> rm -r <directory name>

➤ Remove/Delete non empty directory without prompt

rm -rf <directory name>

➤ Know about a command / Mannual of a command

man <command name>

➤ Get help about a command

<command name> --help

➤ Copy file

cp <filename> <destination>

➤ Move file

mv <filename> <destination>

➤ Rename file

mv <filename> <new name>

➤ Search something from linux file ststem

locate <file/folder word>

➤ Search something ignoring case sensitivity

locate -i <file/folder word>

➤ Search by multiple words

locate -i *<word>*<word>

➤ Write down something into a file

echo <text> >> <filename>

➤ Watch the texts of a file

cat <filename>

➤ Turn off computer

sudo halt

➤ Restart computer

sudo reboot

➤ Open "nano"

nano <filename>

➤ Open "vim"

vi <filename>

➤ Open "jed"

jed <filename>

➤ Do something as an administrator

sudo <command>

➤ Open administrator command line

sudo bash su

➤ Set a root password

sudo passwd

➤ Watch available disk space

df

➤ Watch available disk space in megabite

df -m

➤ Watch the disk usage of all files/folders of system

du

➤ Watch the disk usage of a specific folder/file

df <file/folder name>

➤ Watch file sizes of all the files of a folder

ls -lah

➤ ZIP something

zip <foldername>

➤ UNZIP something

unzip <foldername>

➤ Get information about system

uname

➤ Get detail information about system

uname -a

➤ Watch hostname

hostname

➤ Watch IP addrees

hostname -I

➤ To ping (check internet connection, or check connection to a server)

ping <server>

➤ Remove/Delete a file

rm <filename>

➤ Remove/Delete multiple files

rm <filename> <filename> <filename>

➤ Remove/Delete all file of same extension

rm *.pdf

➤ Confirm each file before removing

rm -i <filename>

➤ Remove/Delete file without prompt

rm -f <filename>

➤ Get interactive root shell

sudo -i

➤ Add administrator to run sudo

sudo adduser <username> sudo

➤ Enable root account

sudo passwd root

➤ Edit sudo configuration

sudo visudo

➤ Know date

date

➤ Know computer uptime

uptime

➤ Read a file

cat <filename>

➤ Read multiple file simultaneously

cat <filename> <filename>

➤ Analyze a file

wc <filename>

➤ See the diffrence btween two files

diff <filename> <filename>

➤ Show output text in one line

less <filename>

➤ Find and replace text of a file

sed -i 's/<text to replace>/<text to be replaced>/g' <filename>

➤ See info of a command

info <command>

Ex: info grep

➤ See manual of a command

man <command>

Ex: man grep

➤ To logout

logout

➤ To shutdown (must be with root permission)

shutdown -h now

➤ To reboot (must be with root permission)

shutdown -r now

➤ Get alias list

alias

➤ Set an alias

alias [name="value"]
Ex: alias p="pwd"

➤ Remove alias from current user alias list

unalias <alias_name>

Bash/Terminal related command

➤ Know your bash version

bash --version

➤ Know your bash history

history

➤ Add a new environment variable for this session (will be vanished after closing bash)

export <MYVAR>=<VARVALUE>

➤ Remove an environment variable from current session

unset <MYVAR>

➤ Update current session with changes made in .bashrc / .bash_profile / bash.bashrc / /etc/profile file

source .bashrc
source .bash_profile
source bash.bashrc
source /etc/profile

➤ Clear terminal window

clear

➤ Exit from terminal

exit

➤ Search from previous commands

CTRL + R

➤ List out all the current session environment variables

env

➤ Add directory to $PATH

Step 1: Add dir to ~/.bash_profile

echo 'export PATH="$PATH:[NEW_DIR_LOCATION_TO_ADD_TO_PATH]”’ >> ~/.bash_profile

Step 2: Reload to make the changes available to the current shell

source ~/.bash_profile
Or
. ~/.bash_profile

Step 3: Verify that the directory is in the $PATH

echo $PATH

Permission related commands

➤ Make a file executable

chmod +x <filename>

➤ Make a file executable as administrator

chmod 755 <filename>

➤ Make a file root executable

chmod +x <filename>

APT (package manager) commands

➤ Install a package

apt-get <package name>

➤ Update repository

apt-get update

➤ Upgrade system

apt-get upgrade

➤ Only upgrade a sinlge package

apt-get install --only-upgrade <Package Name>

➤ Upgrade distro

apt-get dist-upgrade

➤ Search for a package

apt-cache search <package name>

Tar commands

➤ Create a new tar archive

tar cvf archive_name.tar dirname/
tar cvfz archive_name.tar.gz dirname/
tar cvfz archive_name.tgz dirname/
tar cvfj archive_name.tar.bz2 dirname/
tar cvfj archive_name.tb2 dirname/
tar cvfj archive_name.tbz dirname/

Description:

Term	Description
c	Create a new archive
v	Verbosely list files which are processed
f	Following is the archive file name
z	Filter the archive through gzip
j	Filter the archive through bzip2

NB:

• .tgz is same as .tar.gz
• .tb2 and .tbz are same as .tar.bz2
• bzip2 takes more time to compress and decompress than gzip. But bzip2 archival size is less than gzip

➤ Extract from an existing tar archive

tar xvf archive_name.tar

Description:

Term	Description
x	Extract files from archive

➤ Extract a gzipped tar archive

tar xvfz archive_name.tar.gz

➤ Extract a bzipped tar archive

tar xvfj archive_name.tar.gz

NB:

• In all above commands, v is optional

➤ View an existing tar archive

tar tvf archive_name.tar

Grep commands

➤ Search for a given string in a file (case in-sensitive search)

grep -i "the" demo_file