--- name: "mtree" section: "5" platform: "linux" package: "libarchive" version: "3.8.11-1" release: "Arch Linux 2026-11-01" platforms: ["linux", "freebsd", "macos"] url: "https://new.carta.tech/mtree/5" --- # mtree(5) format of mtree dir hierarchy files ## 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. ### 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 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: - 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)](/cksum/1.md) utility. - **device** The device number for **block** or **char** file types. The value must be one of the following forms: - *format*,*major*,*minor*\[,*subunit*\] A device with *major*, *minor* and optional *subunit* fields. Their meaning is specified by the operating system's *format*. See below for valid formats. - *number* Opaque number (as stored on the file system). The following values for *format* are recognized: **native**, **386bsd**, **4bsd**, **bsdos**, **freebsd**, **hpux**, **isc**, **linux**, **netbsd**, **osf1**, **sco**, **solaris**, **sunos**, **svr3**, **svr4**, and **ultrix**. See [mknod(8)](/mknod/8.md) for more details. - **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)](/chflags/1.md) 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. - **inode** The inode number. - **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. - **optional** The file is optional; do not complain about the file if it is not in the file hierarchy. - **resdevice** The “resident” device number of the file, e.g. the ID of the device that contains the file. Its format is the same as the one for **device**. - **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**. - **sha384** The FIPS 180-2 (“SHA-384”) message digest of the file. - **sha384digest** A synonym for **sha384**. - **sha512** The FIPS 180-2 (“SHA-512”) message digest of the file. - **sha512digest** A synonym for **sha512**. - **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)](/cksum/1.md), [find(1)](/find/1.md), [mtree(8)](/mtree/8.md) ## 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)](/cksum/1.md). 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.