The umask command displays or sets the creation mask setting. The creation mask setting defines the default attributes for new files (see section [*]). If no argument is included, umask displays the current setting. To change the creation mask setting type
umask value
where value is a three digit octal number similar to the
one defined in section [*]. It is important to note
that this is a mask. This means that a umask setting of
022 would give the owner full privileges while the group and
all others would not have write privileges. This is exactly opposite
of what we saw in section [*] on chmod.