mtree
—
format of mtree dir hierarchy files
The mtree
format is a textual format that describes a
collection of filesystem objects. Such files are typically used to create or
verify directory hierarchies.
An mtree
file consists of a series of lines, each
providing information about a single filesystem object. Leading whitespace is
always ignored.
When encoding file or pathnames, any backslash character or
character outside of the 95 printable ASCII characters must be encoded as a
backslash followed by three octal digits. When reading mtree files, any
appearance of a backslash followed by three octal digits should be converted
into the corresponding character.
Each line is interpreted independently as one of the following
types:
- Blank
- Blank lines are ignored.
- Comment
- Lines beginning with
#
are ignored.
- Special
- Lines beginning with
/
are special commands that
influence the interpretation of later lines.
- Relative
- If the first whitespace-delimited word has no
/
characters, it is the name of a file in the current directory. Any
relative entry that describes a directory changes the current
directory.
- dot-dot
- As a special case, a relative entry with the filename
.. changes the current directory to the parent
directory. Options on dot-dot entries are always ignored.
- Full
- If the first whitespace-delimited word has a
/
character after the first character, it is the pathname of a file relative
to the starting directory. There can be multiple full entries describing
the same file.
Some tools that process mtree
files may
require that multiple lines describing the same file occur consecutively. It
is not permitted for the same file to be mentioned using both a relative and
a full file specification.
Two special commands are currently defined:
/set
- This command defines default values for one or more keywords. It is
followed on the same line by one or more whitespace-separated keyword
definitions. These definitions apply to all following files that do not
specify a value for that keyword.
/unset
- This command removes any default value set by a previous
/set
command. It is followed on the same line by
one or more keywords separated by whitespace.
After the filename, a full or relative entry consists of zero or more
whitespace-separated keyword definitions. Each such definition consists of a
key from the following list immediately followed by an '=' sign and a value.
Software programs reading mtree files should warn about unrecognized keywords.
Currently supported keywords are as follows:
cksum
- The checksum of the file using the default algorithm specified by the
cksum(1) utility.
device
- The device number for block or char
file types. The value must be one of the following forms:
- format,major,minor[,subunit]
- A device with major, minor
and optional subunit fields. Their meaning is
specified by the operating's system format. See
below for valid formats.
- number
- Opaque number (as stored on the file system).
The following values for format are
recognized: native, 386bsd,
4bsd, bsdos,
freebsd, hpux,
isc, linux,
netbsd, osf1, sco,
solaris, sunos,
svr3, svr4, and
ultrix.
See mknod(8) for
more details.
contents
- The full pathname of a file that holds the contents of this file.
flags
- The file flags as a symbolic name. See
chflags(1) for information
on these names. If no flags are to be set the string “none”
may be used to override the current default.
gid
- The file group as a numeric value.
gname
- The file group as a symbolic name.
ignore
- Ignore any file hierarchy below this file.
inode
- The inode number.
link
- The target of the symbolic link when type=link.
md5
- The MD5 message digest of the file.
md5digest
- A synonym for
md5
.
mode
- The current file's permissions as a numeric (octal) or symbolic
value.
nlink
- The number of hard links the file is expected to have.
nochange
- Make sure this file or directory exists but otherwise ignore all
attributes.
optional
- The file is optional; do not complain about the file if it is not in the
file hierarchy.
resdevice
- The “resident” device number of the file, e.g. the ID of the
device that contains the file. Its format is the same as the one for
device
.
ripemd160digest
- The RIPEMD160 message digest of the file.
rmd160
- A synonym for
ripemd160digest
.
rmd160digest
- A synonym for
ripemd160digest
.
sha1
- The FIPS 160-1 (“SHA-1”) message digest of the file.
sha1digest
- A synonym for
sha1
.
sha256
- The FIPS 180-2 (“SHA-256”) message digest of the file.
sha256digest
- A synonym for
sha256
.
sha384
- The FIPS 180-2 (“SHA-384”) message digest of the file.
sha384digest
- A synonym for
sha384
.
sha512
- The FIPS 180-2 (“SHA-512”) message digest of the file.
sha512digest
- A synonym for
sha512
.
size
- The size, in bytes, of the file.
time
- The last modification time of the file.
type
- The type of the file; may be set to any one of the following:
block
- block special device
char
- character special device
dir
- directory
fifo
- fifo
file
- regular file
link
- symbolic link
socket
- socket
uid
- The file owner as a numeric value.
uname
- The file owner as a symbolic name.
The mtree
utility appeared in
4.3BSD-Reno. The MD5 digest capability was added in
FreeBSD 2.1, in response to the widespread use of
programs which can spoof
cksum(1). The SHA-1 and RIPEMD160
digests were added in FreeBSD 4.0, as new attacks have
demonstrated weaknesses in MD5. The SHA-256 digest was added in
FreeBSD 6.0. Support for file flags was added in
FreeBSD 4.0, and mostly comes from
NetBSD. The “full” entry format was
added by NetBSD.