umask command in unix

What is umask?
It is a number which define the default permissions which are not given on a file or directory.

Calculation of Umask:
You can simply subtract the umask from the base permissions to determine the final permission for file as follows.

Suppose umask 000
It means User has 0, Group has 0 and other has also 0
It means folder permission
User permission is      7-0 =7 (Read, Write and Execute)
Group Permission is   7-0 =7 (Read, Write and Execute)
Other Permission is    7-0 =7 (Read, Write and Execute)


Suppose umask 002
It means User has 0, Group has 0 and other has 2
It means folder permission
User permission is     7-0 =7 (Read, Write and Execute)
Group Permission is   7-0 =7 (Read, Write and Execute)
Other Permission is    7-2 =5 (Read and Execute)


Suppose umask 022
It means User has 0, Group has 2 and other has 2
It means folder permission
User permission is      7-0 =7 (Read, Write and Execute)
Group Permission is   7-2 =5 (Read and Execute)
Other Permission is    7-2 =5 (Read and Execute)


Suppose umask 027
It means User has 0, Group has 2 and other has 2
It means folder permission
User permission is      7-0 =7 (Read, Write and Execute)
Group Permission is   7-2 =5 (Read and Execute)
Other Permission is    7-7 =0 (No permission)

Umask	User permission	Group permission	Others permission
000	all	all	all
002	all	all	read & execute
022	all	read / execute	read / execute
027	all	read / execute	No permission

How to find out the umask value?

$ umask
0022

How to change the Umask?

$ umask 002

Best Related Posts are Following:

1. linux Interview Questions and Answers for freshers and experienced.
2. umask command in unix.
3. How to add user in linux terminal OR change the password of user..
4. Linux Access logs - List of Columns - Simple commands to view Server Logs.
5. Manage Cron Job with PHP - SSH2 Connection.
6. SVN Important Commands.
7. GitHub in window 7 | GitHub Commands in Linux.