misc/chattr.1.in

   1 .\" -*- nroff -*-
   2 .TH CHATTR 1 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
   3 .SH NAME
   4 chattr \- change file attributes on a Linux second extended file system
   5 .SH SYNOPSIS
   6 .B chattr
   7 [
   8 .B \-RV
   9 ]
  10 [
  11 .B -v
  12 version
  13 ]
  14 [
  15 mode
  16 ]
  17 .I files...
  18 .SH DESCRIPTION
  19 .B chattr
  20 changes the files attributes on an second extended file system.
  21 .PP
  22 The format of a symbolic mode is +-=[ASacdisu].
  23 .PP
  24 The operator `+' causes the selected attributes to be added to the
  25 existing attributes of the files; `-' causes them to be removed; and
  26 `=' causes them to be the only attributes that the files have.
  27 .PP
  28 The letters `ASacdisu' select the new attributes for the files:
  29 don't update atime (A), synchronous updates (S), append only (a),
  30 compressed (c), immutable (i), no dump (d),
  31 secure deletion (s), and undeletable (u).
  32 .SH OPTIONS
  33 .TP
  34 .I -R
  35 Recursively change attributes of directories and their contents.
  36 .TP
  37 .I -V
  38 Verbosely describe changed attributes.
  39 .TP
  40 .I -v version
  41 Set the files version.
  42 .SH ATTRIBUTES
  43 When a file with the 'A' attribute set is modified, its atime record is
  44 not modified.  This avoid a certain amount of disk I/O for laptop
  45 systems.
  46
  47 A file with the `a' attribute set can only be open in append mode for writing.
  48
  49 A file with the `c' attribute set is automatically compressed on the disk
  50 by the kernel. A read from this file returns uncompressed data. A write to
  51 this file compresses data before storing them on the disk.
  52
  53 A file with the `d' attribute set is not candidate for backup when the
  54 .BR dump (8)
  55 program is run.
  56
  57 A file with the `i' attribute cannot be modified: it cannot be deleted or
  58 renamed, no link can be created to this file and no data can be written
  59 to the file. Only the superuser can set or clear this attribute.
  60
  61 When a file with the `s' attribute set is deleted, its blocks are zeroed and
  62 written back to the disk.
  63
  64 When a file with the `S' attribute set is modified,
  65 the changes are written synchronously on the disk; this is equivalent to
  66 the `sync' mount option applied to a subset of the files.
  67
  68 When a file with the `u' attribute set is deleted, its contents is saved.
  69 This allows the user to ask for its undeletion.
  70
  71 .SH AUTHOR
  72 .B chattr
  73 has been written by Remy Card <card@masi.ibp.fr>, the developer and maintainer
  74 of the ext2 fs.
  75 .SH BUGS AND LIMITATIONS
  76 As of ext2 fs 0.5a, the `c' and `u' attribute are not honoured by the kernel
  77 code.  As of the Linux 2.0 kernel, the 'A' attribute is not yet supported by
  78 the kernel code.  (The noatime code is still in testing.)
  79 .PP
  80 These attributes will be implemented in a future ext2 fs version.
  81 .SH AVAILABILITY
  82 .B chattr
  83 is available for anonymous ftp from ftp.ibp.fr and tsx-11.mit.edu in
  84 /pub/linux/packages/ext2fs.
  85 .SH SEE ALSO
  86 .BR lsattr (1)