Linux Permissions

To get a deeper understanding of how the operating system interprets the permissions we have to dig into how bit numbers represent the read/write/execute permissions. The bits are as mentioned before represented by numbers ranging from 0-7. The table below shows what each number represents.



Permission bits – Output text – Numbered value


All types of access are denied  = 0 

Execute access is allowed only = 1

write access is allowed only = 2

write and execute access are allowed = 3 

read access is allowed only = 4

Read and execute access are allowed = 5 

Read and write access are allowed = 6 

Everything is allowed = 7 


Linux Permissions