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 file attributes on a Linux 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 Symbolic links encountered during recursive directory traversals are
  37 ignored.
  38 .TP
  39 .I -V
  40 Be verbose with chattr's output and print the program version.
  41 .TP
  42 .I -v version
  43 Set the files version.
  44 .SH ATTRIBUTES
  45 When a file with the 'A' attribute set is modified, its atime record is
  46 not modified.  This avoids a certain amount of disk I/O for laptop
  47 systems.
  48 .PP
  49 A file with the `a' attribute set can only be open in append mode for writing.
  50 Only the superuser can set or clear this attribute.
  51 .PP
  52 A file with the `c' attribute set is automatically compressed on the disk
  53 by the kernel. A read from this file returns uncompressed data. A write to
  54 this file compresses data before storing them on the disk.
  55 .PP
  56 A file with the `d' attribute set is not candidate for backup when the
  57 .BR dump (8)
  58 program is run.
  59 .PP
  60 A file with the `i' attribute cannot be modified: it cannot be deleted or
  61 renamed, no link can be created to this file and no data can be written
  62 to the file. Only the superuser can set or clear this attribute.
  63 .PP
  64 When a file with the `s' attribute set is deleted, its blocks are zeroed and
  65 written back to the disk.
  66 .PP
  67 When a file with the `S' attribute set is modified,
  68 the changes are written synchronously on the disk; this is equivalent to
  69 the `sync' mount option applied to a subset of the files.
  70 .PP
  71 When a file with the `u' attribute set is deleted, its contents are saved.
  72 This allows the user to ask for its undeletion.
  73 .PP
  74 .SH AUTHOR
  75 .B chattr
  76 was written by Remy Card <card@masi.ibp.fr>, the developer and maintainer
  77 of the ext2 fs.
  78 .SH BUGS AND LIMITATIONS
  79 As of ext2 fs 0.5a, the `c' and `u' attribute are not honoured by the kernel
  80 code.  As of the Linux 2.0 kernel, the 'A' attribute is not yet supported by
  81 the kernel code.  (The noatime code is still in testing.)
  82 .PP
  83 These attributes will be implemented in a future ext2 fs version.
  84 .SH AVAILABILITY
  85 .B chattr
  86 is part of the e2fsprogs package and is available for anonymous
  87 ftp from tsx-11.mit.edu in /pub/linux/packages/ext2fs.
  88 .SH SEE ALSO
  89 .BR lsattr (1)