.B chattr
changes the file attributes on a Linux file system.
.PP
-The format of a symbolic mode is +-=[aAcCdDeFijPsStTux].
+The format of a symbolic mode is +-=[aAcCdDeFijmPsStTux].
.PP
The operator '+' causes the selected attributes to be added to the
existing attributes of the files; '-' causes them to be removed; and '='
causes them to be the only attributes that the files have.
.PP
-The letters 'aAcCdDeFijPsStTux' select the new attributes for the files:
+The letters 'aAcCdDeFijmPsStTux' select the new attributes for the files:
append only (a),
no atime updates (A),
compressed (c),
case-insensitive directory lookups (F),
immutable (i),
data journalling (j),
+don't compress (m),
project hierarchy (P),
secure deletion (s),
synchronous updates (S),
attribute has no effect. Only the superuser or a process possessing the
CAP_SYS_RESOURCE capability can set or clear this attribute.
.TP
+.B m
+A file with the 'm' attribute is excluded from compression on file
+systems that support per-file compression.
+.TP
.B N
A file with the 'N' attribute set indicates that the file has data
stored inline, within the inode itself. It may not be set or cleared