CHATTR(1)

NAME
       chattr - change file attributes on a Linux second extended
       file system

SYNOPSIS
       chattr [ -RV ] [ -v version ] [ mode ] files...

DESCRIPTION
       chattr changes the files attributes on an second  extended
       file system.

       The format of a symbolic mode is +-=[ASacdisu].

       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.

       The letters `ASacdisu' select the new attributes  for  the
       files:  don't  update  atime (A), synchronous updates (S),
       append only (a), compressed (c), immutable  (i),  no  dump
       (d), secure deletion (s), and undeletable (u).

OPTIONS
       -R     Recursively  change  attributes  of directories and
              their contents.

       -V     Verbosely describe changed attributes.

       -v version
              Set the files version.

ATTRIBUTES
       When a file with the 'A' attribute set  is  modified,  its
       atime record is not modified.  This avoid a certain amount
       of disk I/O for laptop systems.

       A file with the `a' attribute set  can  only  be  open  in
       append mode for writing.

       A  file  with  the `c' attribute set is automatically com-
       pressed on the disk by the kernel. A read from  this  file
       returns uncompressed data. A write to this file compresses
       data before storing them on the disk.

       A file with the `d' attribute set  is  not  candidate  for
       backup when the dump(8) program is run.

       A  file with the `i' attribute cannot be modified: it can-
       not be deleted or renamed, no link can be created to  this
       file  and  no  data  can  be written to the file. Only the
       superuser can set or clear this attribute.

       When a file with the `s' attribute  set  is  deleted,  its

       blocks are zeroed and written back to the disk.

       When  a  file  with the `S' attribute set is modified, the
       changes are written synchronously on  the  disk;  this  is
       equivalent  to the `sync' mount option applied to a subset
       of the files.

       When a file with the `u' attribute  set  is  deleted,  its
       contents  is  saved.   This allows the user to ask for its
       undeletion.

AUTHOR
       chattr has been written by Remy  Card  lt;card@masi.ibp.fr,
       the developer and maintainer of the ext2 fs.

BUGS AND LIMITATIONS
       As of ext2 fs 0.5a, the `c' and `u' attribute are not hon-
       oured by the kernel code.  As of the Linux 2.0 kernel, the
       'A'  attribute  is  not  yet supported by the kernel code.
       (The noatime code is still in testing.)

       These attributes will be implemented in a future  ext2  fs
       version.

AVAILABILITY
       chattr  is available for anonymous ftp from ftp.ibp.fr and
       tsx-11.mit.edu in /pub/linux/packages/ext2fs.

SEE ALSO
       lsattr(1)