2 .TH CHATTR 1 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
4 chattr \- change file attributes on a Linux second extended file system
20 changes the file attributes on a Linux second extended file system.
22 The format of a symbolic mode is +-=[ASacdisu].
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.
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).
35 Recursively change attributes of directories and their contents.
36 Symbolic links encountered during recursive directory traversals are
40 Be verbose with chattr's output and print the program version.
43 Set the filesystem version.
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
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.
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.
56 A file with the `d' attribute set is not candidate for backup when the
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.
64 When a file with the `s' attribute set is deleted, its blocks are zeroed and
65 written back to the disk.
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.
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.
76 was written by Remy Card <card@masi.ibp.fr>, the developer and maintainer
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.)
83 These attributes will be implemented in a future ext2 fs version.
86 is part of the e2fsprogs package and is available for anonymous
87 ftp from tsx-11.mit.edu in /pub/linux/packages/ext2fs.