Chatter is a utility you’d find on most Linux systems, it’s sole purpose is to change file attributes.
when you use Chattr you’ll probably use it in symbolic mode, this means you will be using +, – and =(plus, minus and equals) plus either of the attributes: A, S, a, c, D, d, I, i, j, s, T, t, u.
Symbols
+ adds a attribute
- removes a attribute
= causes the attribute to be the only
Attributes
a (small A) is append only, this only allows someone to add to a file.
c (small C) is compressed
d (small D) is no dump
i (small I) is immutable, meaning no delete for anyone, not even root
j (small J) is journaling
s (small S) is secure deletion, incase you want to remove a file completely with no way of recovery(except IBAS)
t (small T) is no tailing
u (small U) is undeleteable
A (capital A) is no atime updates
D (capital D) is synchronousdirectory updates
S (capital S) is synchronous updates
T (capital T) is top of directory hierarchy, useful for important files
Options
As with most commands you got options as well
chattr got most of the common ones:
-R, recursive
-V, verbose
-f, suppress most errors
-v, version
options go first of course
Common use
most of the time you won’t use all of these options, but some you will run into quite often would be
chattr +i/chattr =i to protect files from accidental deletion
chattr +T to make a important file top of the file listings
chattr +d to prevent dumping of a file
and in some rare cases
chattr +ad to only allowing appending and prevent backup using
dump
, this could be useful for log files etc. that you only want to be appended to and not backed up