Showing posts with label file and directory permission. Show all posts
Showing posts with label file and directory permission. Show all posts

Thursday, March 28, 2013

Linux File Permission Mechanism

Linux File Permissions :

Understanding Linux File & Directory Permissions :



Linux File and directory Permission mechanism

Read Write Execute
Owner 400 200 100
Group 40 20 10
Others 4 2 1


If you want to give Read, Write & Execute permission to Owner, Groups & Others, it means full permission.
400+200+100+40+20+10+4+2+1 = 777

If you do not want to give Write permission to Groups Others, it means 
400+200+100+40+10+4+1 = 755

The best thing of this calculation, you can not make sum of a number in two different ways .
It means 644 can be made in this way only that is 400+200+40+4
The meaning of 644 is Read & Write permission to Owner and Read permission to Group and Others only.

To give 777 to a directory :

# chmod -R 777 /path/of/the/directory

where -R means Recursive, it means give this permission to all sub-directories and files.

To give 777 to a file :
# chmod 777 /path/of/the/file
Now you can create & give permissions by your own.