AN INTRO TO UNIX/LINUX COMMANDS BY: JIAYANG WANG

WHAT IS UNIX? Operating system developed in the 1960s Still being developed Usually Command line based Multiuser and multitasking You can read more about UNIX here:

USEFUL SOFTWARE FOR CONNECTING TO REMOTE MACHINE PuTTY: Free SSH Client – Allows you to remotely connect to another machine in a secure way Filezilla: Free FTP Software – Allows you to transfer files to and from another machine

HOW TO GET TO THE TERMINAL IN KALI

HOW TO NAVIGATE ls (list) – this command shows all the files and subdirectories of your current directory. ls –hal : better version (human readable, all, long listing format). cd (Change Directory): this command changes your directory to the specified one. Example %cd desktop will take you to the desktop directory Example %cd.. Will take you to the parent directory pwd (print working directory): shows you where you are in relation to the whole file system.

HOW TO CREATE NEW DIRECTORY(FOLDER) mkdir (make directory): Allows you to create a directory(folder) in your current directory Similar to right clicking and choosing new folder in windows Example: mkdir newdirectory

HOW TO VIEW CONTENTS OF A FILE cat (concatenate): displays contents of the file to the screen Example: %cat randomfile.txt less: displays contents of the file to the screen a page at a time Example: %less randomfile.txt [space-bar] to visit next page, [q] to quit

HOW TO SEARCH A FILE FOR KEYWORDS Grep: searches files for specific words or patterns Example of searching for the word password in passwords.txt: %grep password password.txt Example of searching for a phrase in password.txt: %grep ‘my password’ password.txt Example of search for a phrase in a directory: grep -R 'string' dir/

UNIX TEXT EDITORS Nano: very simple to use editor, we will be using nano in our tutorial Vim: a bit more complex to use but it is very powerful and very rewarding when mastered

HOW TO TOUCH Touch: creates a empty file %touch me.txt

CREATE A FILE USING NANO %nano filename Example c file: %nano sample.c Example c++ file: %nano sample.cpp Example java file: %nano sample.java

SAVING A FILE IN NANO Press ctrl-o to save the file Press ctrl-x to exit nano will ask you if you want to save, press y to save press n to not save It will prompt you to enter a file name After editing the file name, you can press enter

HOW TO COMPILE A C FILE IN UNIX gcc filename.c This will create an executable called a.out You can run the executable by running./a.out gcc filename.c –o executablename This will create an executable with whatever name you specify You can run the executable by running./executablename

HOW TO COMPILE A C++ FILE IN UNIX Very similar to c g++ filename.cpp This will create an executable called a.out You can run the executable by running./a.out g++ filename.cpp –o executablename This will create an executable with whatever name you specify You can run the executable by running./executablename

HOW TO COMPILE A JAVA PROGRAM IN UNIX javac filename.java This will create a.class file called filename.class java filename This will run the application

HOW TO DELETE A FILE %rm filename: deletes the file

HOW TO DELETE A DIRECTORY %rmdir directoryname: removes the directory %rm -rf directoryname: removes the directory and its contents

WANT TO LEARN MORE? HERES SOME GREAT RESOURCES UNIX Tutorial for Beginners: Learn UNIX the hard way: