Manual Pages  — MTREE

mtree – format of mtree dir hierarchy files

DESCRIPTION General Format Special commands Keywords SEE ALSO HISTORY BUGS

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:

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.

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 definitions 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 whose contents should be compared to 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.
ignore
	Ignore any file hierarchy below this file.
gid	The file group as a numeric value.
gname	The file group as a symbolic name.
md5	The MD5 message digest of the file.
md5digest
	A synonym for md5.
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.
ripemd160digest
	The RIPEMD160 message digest of the file.
rmd160
	A synonym for ripemd160digest.
rmd160digest
	A synonym for ripemd160digest.
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.
uid	The file owner as a numeric value.
uname	The file owner as a symbolic name.
size	The size, in bytes, of the file.
link	The file the symbolic link is expected to reference.
time	The last modification time of the file, in seconds and nanoseconds. The value should include a period character and exactly nine digits after the period.
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

The requirement for a "#mtree" signature line is new and not yet widely implemented.