What is -rw-rw-r– ?!

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Author: Doe Hoon LEE

Linux Permission and Ownership

When you type ls -l on your terminal, you are going to see something like this

• What is ls ?

• ls is short for ‘list’

• simple ls shows visible contents of the current directory

• option -l will show permissions

• option -al will show contents including hidden files

Let’s dig more into it then?

#	Field	What is this ?
1	-rw-rw-r–	- indicates file permission - - indicates regular file
2	1	number of hard link(s)
3	ec2-user	User ownership
4	ec2-user	Group ownership
5	0	file size
6	Feb 23 08:05	Last modified date
7	tutorial.text	name of file/directory

Permission

• The very first field of Permission indicates type of the content

Symbol	Type
-	regular file
d	directory
b	block device
c	character device
l	symlink
p	pipe
s	socket

• From second to last indicate categories and accesses

• There are two ways to represent permission: symbolic and numeric

• r(read) : read the contents of the file

• w(write) : write or modify the file/directory

• x(execute) : execute or view contents

	Owner			Group			Others
Symbolic mode	r	w	x	r	w	x	r	-	-
Numeric mode	4	2	1	4	2	1	4	0	0

• Each numerics are added to see each category’s accessibility (ex. 664 or 777)

• Let’s go back to the terminal and check tutorial.txt !

-rw-rw-r-- 1 ec2-user ec2-user 0 Feb 23 08:05 tutorial.txt

• Can you now tell what this means?

• -rw-rw-r--

This means the owner has the ability to ‘read’ and ‘write’, but other(s) can only read

This can be rewritten in numeric mode

	Owner			Group			Others
Symbolic mode	r	w	-	r	w	-	r	-	-
Numeric mode	4	2	0	4	2	0	4	0	0
Sum		6			6			6

• 1

There is one hard link attached to it

• The first ec2-user is owner name

• The second ec2-user is owner group

• 0

File size is zero

• Feb 23 08:05

This file was last modified on Feb 23rd at 08:05

• tutorial.txt

Name of this file is tutorial.txt