CHATTR(1)                                               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  file  attributes  on  a  Linux  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.  Symbolic links encountered  during
              recursive directory traversals are ignored.

       -V     Be  verbose with chattr's output and print the pro-
              gram version.

       -v version
              Set the files version.

ATTRIBUTES
       When a file with the 'A' attribute set  is  modified,  its
       atime  record  is  not  modified.   This  avoids 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.  Only the superuser can set or
       clear this attribute.

       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 are saved.  This allows the user to ask  for  its
       undeletion.

AUTHOR
       chattr  was  written  by Remy Card <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 part of the e2fsprogs package and  is  available
       for  anonymous ftp from tsx-11.mit.edu in /pub/linux/pack-
       ages/ext2fs.

SEE ALSO
       lsattr(1)

E2fsprogs version 1.14     January 1999                         1