Basic linux Commands

What is Linux?

Linux is a free, open source operating system which works like Windows and Mac OS X. Linux was developed by computer users based on Intel x86 architecture.

Basic Linux Commands

ls - list

 This command is used to view the files, folders directories in which we are.

shows all the files stored in an application.

cd - change directory

  This command is used to go/change to a directory.

mv - move

Command used  to move files and allows to move a file into a folder or directory.

man - manual

 Shows the manual pages of command.

mkdir - make directory  

Command used to create a folder/directory.

rmdir - remove directory

Command used to delete a directory, but rmdir can be used to delete an empty directory.  

tree 

All files and folders will be visible in detailed at screen.

clear

Command used to clear the screen. 

pwd 
This command prints the current location of working directory.

cat
This command used to print the contents of file to the screen.

cp
By using this command we can copy the files from directory

ln
This command is used to link between files and directories.

sudo
We can use this command when we get authorization failure.

head
If we want to print first few lines. we can use this head command.
prints first 20 lines of rsyslogd log.
prints first 10 line by default head command.

tail
Similar like head command but its way opposite function from head.
Prints last 10 lines of default file.

chmod
This command is used to change the file and directory permission.

locate
Basic command used to finde or directory in Linux. It's a database driven command so first have to build the database, and then run and wait for few minutes.

df
This command is used to check the disk space usage on Linux system.
Mostly used along with -h flag.

du
to quickly check disk space usage of a file or directory.

free
This command is used to display the amount of free and used RAM in the system.
along with this command we use -h on side to display in understandable and easier way to read by human.

ifconfig
This command stands for interface configuration, it can so many networking things.

uname 
This command is used for priting the basic information of the system. 
Example- OS name, kenel version, host name etc....

history
This command is used to print the list of previously typed commands. 

md5sum 
This command is used to check whether the file is tempered or not.

mount
This command mounts the file systems on the server. And displays the current file systems and mount locations.