Exam 101-500 topic 1 question 82 discussion

umask 027: dirs 750, files 640

It would actually be 0026 since the default for files is 666. but the best practise is 0027

Default permissions: 777 = default permissions for directories 666 = default for files Default umask: 0002 To change umask: ~$ umask 027 ~$ umask 0027 To check new files have the default permissions -rw-r----- ~$ touch umask-test ~$ ls -l umask-test -rw-r----- 1 neo neo 0 Jan 1 18:01 umask-test Easy explanation: r = 4 w = 2 x = 1 Files with default 002: 666 - 022 = 644 Files with default 027: 666 - 027 = 644 0 = user / 2 = Group / 7 = Others Files: 666 - 027 = 640 = -rw-r-----

0027: Initial 0: ignored second 0: rw for files (rwx for directories) 2: r for files (rx for directories) 7: nothing (for both files and directories)

Closest I can get it to is 026.

this answer is available coz its 0026

Hang on but why it isnt 0137? I though since chmod RW-R---- is 640 I would guess it would be when eliminating the numbers 0/7/7/7 -0/6/4/0 0/1/3/7 can someone explain please?

Why not 0026? isn't these files with starting permissions of 666?