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.
cksum(1),
find(1),
mtree(8)
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.