modifies the set of extended inode flags associated with the current file
Examples:
'chattr +a' - sets the append-only flag
'chattr -a' - clears the append-only flag
-R -- recursively descend (useful when current file is a directory)
-D -- recursively descend, only modifying attributes on directories
+/-r -- set/clear the realtime flag
+/-i -- set/clear the immutable flag
+/-a -- set/clear the append-only flag
+/-s -- set/clear the sync flag
+/-A -- set/clear the no-atime flag
+/-d -- set/clear the no-dump flag
+/-t -- set/clear the realtime inheritance flag
+/-P -- set/clear the project ID inheritance flag
+/-n -- set/clear the no-symbolic-links flag
+/-e -- set/clear the extent-size flag
+/-E -- set/clear the extent-size inheritance flag
+/-f -- set/clear the no-defrag flag
+/-S -- set/clear the filestreams allocator flag
Note1: user must have certain capabilities to modify immutable/append-only.
Note2: immutable/append-only files cannot be deleted; removing these files
requires the immutable/append-only flag to be cleared first.
Note3: the realtime flag can only be set if the filesystem has a realtime
section, and the (regular) file must be empty when the flag is set.
