# https://www.computerhope.com/unix/uchmod.htm
chmod options permissions file name
#Example:
chmod u=rwx,g=rx,o=r myfile
# u, g, and o stand for "user", "group", and "other".
# user can read, write, and execute it;
# members of your group can read and execute it;
# others may only read it.
chmod 754 myfile
# 7 is the combination of permissions 4+2+1 (read, write, and execute),
# 5 is 4+0+1 (read, no write, and execute), and
# 4 is 4+0+0 (read, no write, and no execute).
# 4 stands for "read",
# 2 stands for "write",
# 1 stands for "execute", and
# 0 stands for "no permission."
#Viewing File permissions
ls -l file.txt
clear Clear screen.
date Print current date
nano example.txt Opens the file example.txt in “Nano”, the Linux text editor.
#To be able to update the list of available software
sudo apt-get update
sudo apt-get install tree #Installing a package
#Inform the user how much disk space the package will take up
#And asks for confirmation of the package installation
#Entering Y (or just hitting Enter, as yes is the default action) will allow the installation to occur.
#This can be bypassed by adding the -y flag to the command:
sudo apt-get install tree -y
sudo apt-get remove tree #UnInstalling a package
#PURGE
sudo apt-get purge tree #Completely remove the package and its associated configuration files
sudo apt-get update #Update existing software
sudo apt-get upgrade #Upgrade all of your packages
sudo apt-get install somepackage #Upgrade a specific package
apt-cache search locomotive #Searching for softwares
apt-cache show sl #View Information about a package before installing
# Store or extract files from a tape archive file.
# Compress File:
tar -cvzf *filename.tar.gz* *directory/*
# Decompress File conents:
tar -xvzf *filename.tar.gz*
# Compress in gzip format
gzip file1
# Decompress gzip file
gunzip file1.gz