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.