File System and basic commands

Introduction

In this blog post, you will learn the Linux file system and basic commands, it will be good if you learn them practically in your system.

File System

Parrot OS adheres to the filesystem hierarchy standard. The Filesystem Hierarchy Standard defines the directory structure and directory contents in Linux distros.

Parrot Directories and Description

Below are some important directories of Parrot(Linux).

  • / - Its root directory.
  • /bin - basic programs available for all users.
  • /sbin - contains binary executables for root user only.
  • /dev - Contains device drivers.
  • /etc - Contains configuration files.
  • /lib - It contains shared library files.
  • /tmp - Temporary files which typically deleted on boot.
  • /usr/bin - It contains users binaries.
  • /usr/sbin - It contains root user binaries or system binaries.
  • /usr/share - It contains application support and data files
  • /home - User home directory.
  • ~ - User default working directory.

There are many other directories also, but I only mentioned which we use mostly.

Basic Commands

  • cd - to change directory(usage: cd dirname)
  • ls - list files (usage: ls /home, ls)
  • ls -la -> to list files in details
  • pwd - print working directory(usage: pwd)
  • cat - print file content (usage: cat filename)
  • more - It also print file content (usage: more filename)
  • cp - to copy files (usage: cp file /dir/newname)
  • mv - to move files(mv file /dir/newname
  • mkdir - create directory(usage: - mkdir hacker)
  • rm - remove file(usage: rm hacker.txt)
  • rmdir - remove directory(usage: rmdir hacker)
  • touch - create blank file (usage: touch hacker.txt)
  • whereis - show to location of file (usage: whereis cat)
  • locate - find files by name ( usage: locate ping)
  • man - very useful system commands manual ( usage: man

There are many commands please have a look

Basic network commands and utilities

  • ping
  • arp
  • telnet
  • ifconfig
  • iptables
  • netstat
  • route
  • traceroute
  • ss

Use them one by one, read manual using ‘man’ command

Basic system commands and utilities

  • whomai
  • hostname
  • w
  • lslogin
  • sudo
  • dpkg
  • ps
  • users
  • crontab
  • less
  • more
  • apt
  • service
  • free
  • top
  • mem
  • grep
  • awk
  • find
  • lsof
  • last
  • kill
  • uname
  • watch
  • df
  • dd

Terminal

  • ’$: specifies, you’re in user shell.’
  • ’#: specifies, you’re in root.’

chown command

chown command changes the user and/or group ownership of for given file.

chown owner-user file 
chown owner-user:owner-group file
chown owner-user:owner-group directory
chown options owner-user:owner-group file

chmod command

To change access permissions, change mode.

we can edit permissions using chmod command

$ chmod permissions file

There are three types of Linux users

    1. owner
    1. group
    1. world

There are three types of permissions that Linux allows for each file.

    1. read(4 or r)
    1. write(2 or w)
    1. execute(1 or x)

So, try wrapping your head around this!!

  • 7 = 4+2+1 (read/write/execute)
  • 6 = 4+2 (read/write)
  • 5 = 4+1 (read/execute)
  • 4 = 4 (read)
  • 3 = 2+1 (write/execute)
  • 2 = 2 (write)
  • 1 = 1 (execute)

examples:-

chmod 777 hacker.sh   

chmod 600 hacker.sh

Try it !!!

There are many more, have a look, and read manual using ‘man’ command on terminal. And if you want a tool to help you simple use -h or –help, example ping -h.