format is a textual format that describes a collection of filesystem objects. Such files are typically used to create or verify directory hierarchies.
General Format
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.
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.