А umask 0022 это не делает?
Нет.
Ну давай man umask вместо тебя сделаю:
Description
umask displays and manipulates the 'umask', or file creation mode mask,
which is used to restrict the default access to files.
The umask may be expressed either as an octal number, which represents
the rights that will be removed by default, or symbolically, which
represents the only rights that will be granted by default.
Access rights are explained in the manual page for the chmod(1)
program.