— map a
The utility mtree
compares the file hierarchy
rooted in the current directory against a specification read from the standard
input. Messages are written to the standard output for any files whose
characteristics do not match the specification, or which are missing from
either the file hierarchy or the specification. For an explanation of the
directory hierarchy, see
The options are as follows:
- Print a specification for the file hierarchy to the
- Ignore everything except directory type files.
- Don't complain about files that are in the file hierarchy,
but not in the specification.
- Read the specification from file
spec, instead of from the standard
- Indents the output 4 spaces each time a directory level is
descended when creating a specification with the
-c option. This does not affect either the
/set statements or the comment before each directory. It does however
affect the comment before the close of each directory.
- Add the specified (whitespace or comma separated) keywords
to the current set of keywords.
- Use the “type” keyword plus the specified
(whitespace or comma separated) keywords instead of the current set of
- Do “loose” permissions checks, in which more
stringent permissions will match less stringent ones. For example, a file
marked mode 0444 will pass a check for mode 0644. “Loose”
checks apply only to read, write and execute permissions -- in particular,
if other bits like the sticky bit or suid/sgid bits are set either in the
specification or the file, exact checking will be performed. This flag may
not be set at the same time as the -u or
- Do not emit pathname comments when creating a
specification. Normally a comment is emitted before each directory and
before the close of that directory when using the
- Use the file hierarchy rooted in
path, instead of the current
- Quiet mode. Do not complain when a “missing”
directory cannot be created because it already exists. This occurs when
the directory is a symbolic link.
- Remove any files in the file hierarchy that are not
described in the specification.
- Display a single checksum to the standard error output that
represents all of the files for which the keyword
cksum was specified. The checksum is seeded
with the specified value.
- If a file's timestamp is different from the specification,
“touch” it to match the specification (and list as
- Modify the owner, group, and permissions of existing files
to match the specification and create any missing directories. User,
group, and permissions must all be specified for missing directories to be
created. Exit with a status of 0 on success, 1 if any error occurred; a
mismatch is not considered an error if it was corrected.
- Same as the -U option except a
status of 2 is returned if the file hierarchy did not match the
- Don't descend below mount points in the file
Specifications are mostly composed of “keywords” (i.e., strings
that specify values relating to files). No keywords have default values, and
if a keyword has no value set, no checks based on it are performed.
Currently supported keywords are as follows:
- The checksum of the file using the default algorithm
specified by the
- The current file's flags (whitespace or comma separated) in
symbolic form as specified by
string “none” may be used to indicate that no flags should
be set on the file.
- The file group as a numeric value.
- The file group as a symbolic name.
- Ignore any file hierarchy below this file.
- The file the symbolic link is expected to reference.
- The MD5 message digest of the file.
- The current file's permissions as a numeric (octal) or
- The number of hard links the file is expected to have.
- Do not change the attributes (owner, group, mode, etc) on a
file or directory.
- The file is optional; don't complain about the file if it's
not in the file hierarchy.
- The RIPEMD-160 message digest of the file.
- The SHA-1 message digest of the file.
- The SHA-256 message digest of the file.
- The size, in bytes, of the file.
- The last modification time of the file.
- The type of the file; may be set to any one of the
- block special device
- character special device
- regular file
- symbolic link
- The file owner as a numeric value.
- The file owner as a symbolic name.
The default set of keywords are gid
, and uid
There are four types of lines in a specification.
The first type of line sets a global value for a keyword, and consists of the
string “/set” followed by whitespace, followed by sets of
keyword/value pairs, separated by whitespace. Keyword/value pairs consist of a
keyword, followed by an equals sign (‘=’), followed by a value,
without whitespace characters. Once a keyword has been set, its value remains
unchanged until either reset or unset.
The second type of line unsets keywords and consists of the string
“/unset”, followed by whitespace, followed by one or more
keywords, separated by whitespace.
The third type of line is a file specification and consists of a file name,
followed by whitespace, followed by zero or more whitespace separated
keyword/value pairs. The file name may be preceded by whitespace characters.
The file name may contain any of the standard file name matching characters
(“[”, “]”, “?”, or
“*”), in which case files in the hierarchy will be associated
with the first pattern that they match.
Each of the keyword/value pairs consist of a keyword, followed by an equals
sign, followed by the keyword's value, without whitespace characters. These
values override, without changing, the global value of the corresponding
All paths are relative. Specifying a directory will cause subsequent files to be
searched for in that directory hierarchy. Which brings us to the last type of
line in a specification: a line containing only the string “..”
causes the current directory path to ascend one level.
Empty lines and lines whose first non-whitespace character is a hash mark
(‘#’) are ignored.
- system specification directory
utility exits with a status of 0 on
success, 1 if any error occurred, and 2 if the file hierarchy did not match
the specification. A status of 2 is converted to a status of 0 if the
option is used.
To detect system binaries that have been “trojan horsed”, it is
recommended that mtree
run on the file systems, and a copy of the results stored on a different
machine or, at least, in encrypted form. The output file itself should be
digested using the
Then, periodically, mtree
run against the on-line specifications. While it is possible for the bad guys
to change the on-line specifications to conform to their modified binaries, it
is believed to be impractical for them to create a modified specification
which has the same SHA-256 digest as the original.
can be used in combination to create directory hierarchies for distributions
and other such things; the files in /etc/mtree
were used to create almost all directories in a normal binary distribution.
utility appeared in