How to change the umask?

Question

The umask controls the default file creation permissions, 0002 means files will have 664 and directories 775. Setting this (by editing the umask line at the bottom of /etc/profile in my case) means files created by one user will be writable by other users in the www-group without needing to chmod them.

I've looked that up, but I am told:

# The default umask is now handled by pam_umask.  
# See pam_umask(8) and /etc/login.defs.

And here I am blocked as I don't know pam_umask, I want to change the umask to 0002. How to?

Answer 1

From man 8 pam_umask:

EXAMPLES
Add the following line to /etc/pam.d/login to set the user specific umask at login:

               session optional pam_umask.so umask=0022

You can change that value to 0002.

Answer 2

The right place under debian is:

/etc/pam.d/common-session

session optional pam_umask.so umask = #VALUE (e.g. 0026)