NAME¶
mtree —
format of mtree dir hierarchy
files
DESCRIPTION¶
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 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:
- Signature
- The first line of any mtree file must begin with
“#mtree”. If a file contains any full path entries, the first
line should begin with “#mtree v2.0”, otherwise, the first
line should begin with “#mtree v1.0”.
- 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.
Special commands¶
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.
Keywords¶
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.
- 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.
- 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.
- 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.
- 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.
SEE ALSO¶
cksum(1),
find(1),
mtree(8)
BUGS¶
The
FreeBSD implementation of mtree does not currently
support the
mtree 2.0 format. The requirement for a
“#mtree” signature line is new and not yet widely implemented.
HISTORY¶
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.