Common Linux Commands

The most common Linux commands that I use and forget.

* Primarily using Ubuntu from AWS images.

Directory Structure

http://www.howtogeek.com/117435/htg-explains-the-linux-directory-structure-explained/

copy
Commands
	View current sessions
		who
	apt-get
	apt-get update
	sudo apt-get update
	sudo apt-get autoclean
		remove files that can't be downloaded anymore
	sudo apt-get autoremove
		remove unused dependencies
	adduser
	reboot
	sudo passwd
		change root password
	su
		login as root	
	sudo service SERVICENAME status/start/stop/restart
	copy directory and contents
		cp -r dirSource dirDestination
	create an empty file
		touch filename.txt
	get ip address
		 /sbin/ifconfig
		 hostname -I
	sudo pkill -u username
	delete non-empty directory
		rm -rf myDirectory
	change file/directory owner
		sudo chown username:group directory
		Recursively
			sudo chown -R username:group directory
	Run a Shell Script
		sh myshellscript.sh
			or
		bash myshellscript.sh
	Find a file
		by name
			find -name "filename"
		by name (ignore case)
			find -iname "filename"
	List Top Processes
		top
	List All Users
		cat /etc/passwd
	Add User
		adduser new_username
	
Apache
	edit config file
		pico /etc/apache2/apache2.conf
	install apache
		sudo apt-get install apache2
	restart apache
		sudo service apache2 restart
	error log
		/var/log/apache2/
	sites available
		etc/apache2/sites-available
	disable directory listing
		remove Indexes from apache2.conf/httpd.conf
			ex: Options Includes Indexes FollowSymLinks MultiViews
	Apache rewrite_module
		check if it is installed
			apache2ctl -M
		enabled rewrite_module
			a2enmod rewrite
			restart apache
				service apache2 restart
		allow rewrites in your apache config file		
			<Directory /var/www>
				AllOveride All
		
	apachectl start
	apachectl stop
	apachectl restart
	/sbin/service httpd restart
	apachectl status

MySQL
	sudo apt-get install mysql-client-core-5.6
	sudo apt-get install mysql-server
	sudo apt-get remove --purge mysql-server mysql-client mysql-common
	sudo service mysql restart
	sudo stop mysql
	   
	/etc/init.d/mysqld start
	/etc/init.d/mysqld stop
	/etc/init.d/mysqld restart
	/etc/init.d/mysqld status
	
	Connect to a MySQL Instance
		mysql -u <db-username> -p
		mysql -u root -p
		mysql -h <host> -P <port # optional> -u user -p
		mysql -h something1.something2.us-east-1.rds.amazonaws.com -P 3306 -u root -p
	Execute a command
		select * from mydbname.users;
	Close connection
		quit
		
PHP
	sudo apt-get install php5
	sudo apt-get install php5-gd
	sudo apt-get install php5-mysql
	sudo apt-get install php5 php5-gd php5-mysql
	sudo apt-get install php5-curl
	//possible php.ini paths in Ubunutu
	/etc/php5/apache2
	/etc/php5/cli
	find the php.ini file
		php -i | grep "Loaded Configuration File"
	
Git
	apt-get install libcurl4-gnutls-dev libexpat1-dev gettext
	apt-get install git
	
Tar/Zip
	unzip
		apt-get install unzip
		unzip MyFile.zip
	tar
		compress a directory
			tar -zcvf newfilename.tar.gz my_directory/ 
		decompress a tar file
			tar -zxvf newfilename.tar.gz 
	
Configs
	/etc/apache2/conf/httpd.conf
	
XRDP
	sudo apt-get install xrdp
	
Drupal
	wget http://drupal.org/files/projects/drupal-7.28.tar.gz
	tar -zxvf drupal-7.28.tar.gz
	mv drupal-7.28 /var/www/
	cp -r drupal-7.28 drupal01

AWS
	root/ec2-user/ubuntu
		to login using SSH
		
MISC
	apt-get install wget
	wget http://www.example.com/mystuff.zip
	
ClamAV
	apt-get update
	apt-get install clamav
	Clam UI
		apt-get install clamtk 	
	update virus db
		freshclam
	check all files on the computer, displaying the name of each file
		clamscan -r /
	check all files on the computer, but only display infected files
		clamscan -r -i /
	check all files and output FOUND infected files to file
		clamscan -r / | grep FOUND >> /avreport.txt 
		pico /avreport.txt

Cron - cron job functions
	crontab -l
	crontab -u username -l