tmpfiles.d(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | CONFIGURATION FILE FORMAT | SPECIFIERS | EXAMPLES | /RUN/ AND /VAR/RUN/ | SEE ALSO | NOTES | COLOPHON

TMPFILES.D(5)                  tmpfiles.d                  TMPFILES.D(5)

NAME         top

       tmpfiles.d - Configuration for creation, deletion, and cleaning
       of files and directories

SYNOPSIS         top

           /etc/tmpfiles.d/*.conf
           /run/tmpfiles.d/*.conf
           /usr/lib/tmpfiles.d/*.conf

           ~/.config/user-tmpfiles.d/*.conf
           $XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf
           ~/.local/share/user-tmpfiles.d/*.conf
           ...
           /usr/share/user-tmpfiles.d/*.conf

       #Type Path                                     Mode User Group Age         Argument
       f     /file/to/create                          mode user group -           content
       f+    /file/to/create-or-truncate              mode user group -           content
       w     /file/to/write-to                        -    -    -     -           content
       w+    /file/to/append-to                       -    -    -     -           content
       d     /directory/to/create-and-clean-up        mode user group cleanup-age -
       D     /directory/to/create-and-remove          mode user group cleanup-age -
       e     /directory/to/clean-up                   mode user group cleanup-age -
       v     /subvolume-or-directory/to/create        mode user group cleanup-age -
       q     /subvolume-or-directory/to/create        mode user group cleanup-age -
       Q     /subvolume-or-directory/to/create        mode user group cleanup-age -
       p     /fifo/to/create                          mode user group -           -
       p+    /fifo/to/[re]create                      mode user group -           -
       L     /symlink/to/create                       -    -    -     -           symlink/target/path
       L+    /symlink/to/[re]create                   -    -    -     -           symlink/target/path
       c     /dev/char-device-to-create               mode user group -           major:minor
       c+    /dev/char-device-to-[re]create           mode user group -           major:minor
       b     /dev/block-device-to-create              mode user group -           major:minor
       b+    /dev/block-device-to-[re]create          mode user group -           major:minor
       C     /target/to/create                        -    -    -     cleanup-age /source/to/copy
       C+    /target/to/create                        -    -    -     cleanup-age /source/to/copy
       x     /path-or-glob/to/ignore/recursively      -    -    -     cleanup-age -
       X     /path-or-glob/to/ignore                  -    -    -     cleanup-age -
       r     /path-or-glob/to/remove                  -    -    -     -           -
       R     /path-or-glob/to/remove/recursively      -    -    -     -           -
       z     /path-or-glob/to/adjust/mode             mode user group -           -
       Z     /path-or-glob/to/adjust/mode/recursively mode user group -           -
       t     /path-or-glob/to/set/xattrs              -    -    -     -           xattrs
       T     /path-or-glob/to/set/xattrs/recursively  -    -    -     -           xattrs
       h     /path-or-glob/to/set/attrs               -    -    -     -           file attrs
       H     /path-or-glob/to/set/attrs/recursively   -    -    -     -           file attrs
       a     /path-or-glob/to/set/acls                -    -    -     -           POSIX ACLs
       a+    /path-or-glob/to/append/acls             -    -    -     -           POSIX ACLs
       A     /path-or-glob/to/set/acls/recursively    -    -    -     -           POSIX ACLs
       A+    /path-or-glob/to/append/acls/recursively -    -    -     -           POSIX ACLs

DESCRIPTION         top

       tmpfiles.d configuration files provide a generic mechanism to
       define the creation of regular files, directories, pipes, and
       device nodes, adjustments to their access mode, ownership,
       attributes, quota assignments, and contents, and finally their
       time-based removal. It is mostly commonly used for volatile and
       temporary files and directories (such as those located under
       /run/, /tmp/, /var/tmp/, the API file systems such as /sys/ or
       /proc/, as well as some other directories below /var/).

       systemd-tmpfiles(8) uses this configuration to create volatile
       files and directories during boot and to do periodic cleanup
       afterwards. See systemd-tmpfiles(8) for the description of
       systemd-tmpfiles-setup.service, systemd-tmpfiles-clean.service,
       and associated units.

       System daemons frequently require private runtime directories
       below /run/ to store communication sockets and similar. For
       these, it is better to use RuntimeDirectory= in their unit files
       (see systemd.exec(5) for details), if the flexibility provided by
       tmpfiles.d is not required. The advantages are that the
       configuration required by the unit is centralized in one place,
       and that the lifetime of the directory is tied to the lifetime of
       the service itself. Similarly, StateDirectory=, CacheDirectory=,
       LogsDirectory=, and ConfigurationDirectory= should be used to
       create directories under /var/lib/, /var/cache/, /var/log/, and
       /etc/.  tmpfiles.d should be used for files whose lifetime is
       independent of any service or requires more complicated
       configuration.

CONFIGURATION DIRECTORIES AND PRECEDENCE         top

       Each configuration file shall be named in the style of
       package.conf or package-part.conf. The second variant should be
       used when it is desirable to make it easy to override just this
       part of configuration.

       Files in /etc/tmpfiles.d override files with the same name in
       /usr/lib/tmpfiles.d and /run/tmpfiles.d. Files in /run/tmpfiles.d
       override files with the same name in /usr/lib/tmpfiles.d.
       Packages should install their configuration files in
       /usr/lib/tmpfiles.d. Files in /etc/tmpfiles.d are reserved for
       the local administrator, who may use this logic to override the
       configuration files installed by vendor packages. All
       configuration files are sorted by their filename in lexicographic
       order, regardless of which of the directories they reside in. If
       multiple files specify the same path, the entry in the file with
       the lexicographically earliest name will be applied (note that
       lines suppressed due to the "!"  are filtered before application,
       meaning that if an early line carries the exclamation mark and is
       suppressed because of that, a later line matching in path will be
       applied). All other conflicting entries will be logged as errors.
       When two lines are prefix path and suffix path of each other,
       then the prefix line is always created first, the suffix later
       (and if removal applies to the line, the order is reversed: the
       suffix is removed first, the prefix later). Lines that take globs
       are applied after those accepting no globs. If multiple
       operations shall be applied on the same file (such as ACL, xattr,
       file attribute adjustments), these are always done in the same
       fixed order. Except for those cases, the files/directories are
       processed in the order they are listed.

       If the administrator wants to disable a configuration file
       supplied by the vendor, the recommended way is to place a symlink
       to /dev/null in /etc/tmpfiles.d/ bearing the same filename.

CONFIGURATION FILE FORMAT         top

       The configuration format is one line per path, containing type,
       path, mode, ownership, age, and argument fields. The lines are
       separated by newlines, the fields by whitespace:

           #Type Path        Mode User Group Age Argument...
           d     /run/user   0755 root root  10d -
           L     /tmp/foobar -    -    -     -   /dev/null

       Fields may contain C-style escapes. With the exception of the
       seventh field (the "argument") all fields may be enclosed in
       quotes. Note that any whitespace found in the line after the
       beginning of the argument field will be considered part of the
       argument field. To begin the argument field with a whitespace
       character, use C-style escapes (e.g.  "\x20").

   Type
       The type consists of a single letter and optionally one or more
       modifier characters: a plus sign ("+"), exclamation mark ("!"),
       minus sign ("-"), equals sign ("="), tilde character ("~") and/or
       caret ("^").

       The following line types are understood:

       f, f+
           f will create a file if it does not exist yet. If the
           argument parameter is given and the file did not exist yet,
           it will be written to the file.  f+ will create or truncate
           the file. If the argument parameter is given, it will be
           written to the file. Does not follow symlinks.

       w, w+
           Write the argument parameter to a file, if the file exists.
           If suffixed with +, the line will be appended to the file. If
           your configuration writes multiple lines to the same file,
           use w+. Lines of this type accept shell-style globs in place
           of normal path names. The argument parameter will be written
           without a trailing newline. C-style backslash escapes are
           interpreted. Follows symlinks.

       d
           Create a directory. The mode and ownership will be adjusted
           if specified. Contents of this directory are subject to
           time-based cleanup if the age argument is specified.

       D
           Similar to d, but in addition the contents of the directory
           will be removed when --remove is used.

       e
           Adjust the mode and ownership of existing directories and
           remove their contents based on age. Lines of this type accept
           shell-style globs in place of normal path names. Contents of
           the directories are subject to time-based cleanup if the age
           argument is specified. If the age argument is "0", contents
           will be unconditionally deleted every time
           systemd-tmpfiles(8) --clean is run.

           For this entry to be useful, at least one of the mode, user,
           group, or age arguments must be specified, since otherwise
           this entry has no effect. As an exception, an entry with no
           effect may be useful when combined with !, see the examples.

           Added in version 230.

       v
           Create a subvolume if the path does not exist yet, the file
           system supports subvolumes (btrfs), and the system itself is
           installed into a subvolume (specifically: the root directory
           / is itself a subvolume). Otherwise, create a normal
           directory, in the same way as d.

           A subvolume created with this line type is not assigned to
           any higher-level quota group. For that, use q or Q, which
           allow creating simple quota group hierarchies, see below.

           Added in version 219.

       q
           Create a subvolume or directory the same as v, but assign the
           subvolume to the same higher-level quota groups as the
           parent. This ensures that higher-level limits and accounting
           applied to the parent subvolume also include the specified
           subvolume. On non-btrfs file systems, this line type is
           identical to d.

           If the subvolume already exists, no change to the quota
           hierarchy is made, regardless of whether the subvolume is
           already attached to a quota group or not. Also see Q below.
           See btrfs-qgroup(8) for details about the btrfs quota group
           concept.

           Added in version 228.

       Q
           Create the subvolume or directory the same as v, but assign
           the new subvolume to a new leaf quota group. Instead of
           copying the higher-level quota group assignments from the
           parent as is done with q, the lowest quota group of the
           parent subvolume is determined that is not the leaf quota
           group. Then, an "intermediary" quota group is inserted that
           is one level below this level, and shares the same ID part as
           the specified subvolume. If no higher-level quota group
           exists for the parent subvolume, a new quota group at level
           255 sharing the same ID as the specified subvolume is
           inserted instead. This new intermediary quota group is then
           assigned to the parent subvolume's higher-level quota groups,
           and the specified subvolume's leaf quota group is assigned to
           it.

           Effectively, this has a similar effect as q, however
           introduces a new higher-level quota group for the specified
           subvolume that may be used to enforce limits and accounting
           to the specified subvolume and children subvolume created
           within it. Thus, by creating subvolumes only via q and Q, a
           concept of "subtree quotas" is implemented. Each subvolume
           for which Q is set will get a "subtree" quota group created,
           and all child subvolumes created within it will be assigned
           to it. Each subvolume for which q is set will not get such a
           "subtree" quota group, but it is ensured that they are added
           to the same "subtree" quota group as their immediate parents.

           It is recommended to use Q for subvolumes that typically
           contain further subvolumes, and where it is desirable to have
           accounting and quota limits on all child subvolumes together.
           Examples for Q are typically /home/ or /var/lib/machines/. In
           contrast, q should be used for subvolumes that either usually
           do not include further subvolumes or where no accounting and
           quota limits are needed that apply to all child subvolumes
           together. Examples for q are typically /var/ or /var/tmp/.

           As with q, Q has no effect on the quota group hierarchy if
           the subvolume already exists, regardless of whether the
           subvolume already belong to a quota group or not.

           Added in version 228.

       p, p+
           Create a named pipe (FIFO) if it does not exist yet. If
           suffixed with + and a file already exists where the pipe is
           to be created, it will be removed and be replaced by the
           pipe.

       L, L+
           Create a symlink if it does not exist yet. If suffixed with +
           and a file or directory already exists where the symlink is
           to be created, it will be removed and be replaced by the
           symlink. If the argument is omitted, symlinks to files with
           the same name residing in the directory /usr/share/factory/
           are created. Note that permissions and ownership on symlinks
           are ignored.

       c, c+
           Create a character device node if it does not exist yet. If
           suffixed with + and a file already exists where the device
           node is to be created, it will be removed and be replaced by
           the device node. It is recommended to suffix this entry with
           an exclamation mark to only create static device nodes at
           boot, as udev will not manage static device nodes that are
           created at runtime.

       b, b+
           Create a block device node if it does not exist yet. If
           suffixed with + and a file already exists where the device
           node is to be created, it will be removed and be replaced by
           the device node. It is recommended to suffix this entry with
           an exclamation mark to only create static device nodes at
           boot, as udev will not manage static device nodes that are
           created at runtime.

       C, C+
           Recursively copy a file or directory, if the destination
           files or directories do not exist yet or the destination
           directory is empty. Note that this command will not descend
           into subdirectories if the destination directory already
           exists and is not empty, unless the action is suffixed with
           +. Instead, the entire copy operation is skipped. If the
           argument is omitted, files from the source directory
           /usr/share/factory/ with the same name are copied. Does not
           follow symlinks. Contents of the directories are subject to
           time-based cleanup if the age argument is specified.

           Added in version 214.

       x
           Ignore a path during cleaning. Use this type to exclude paths
           from clean-up as controlled with the Age parameter. Note that
           lines of this type do not influence the effect of r or R
           lines. Lines of this type accept shell-style globs in place
           of normal path names.

       X
           Ignore a path during cleaning. Use this type to exclude paths
           from clean-up as controlled with the Age parameter. Unlike x,
           this parameter will not exclude the content if path is a
           directory, but only directory itself. Note that lines of this
           type do not influence the effect of r or R lines. Lines of
           this type accept shell-style globs in place of normal path
           names.

           Added in version 198.

       r
           Remove a file or directory if it exists. This may not be used
           to remove non-empty directories, use R for that. Lines of
           this type accept shell-style globs in place of normal path
           names. Does not follow symlinks.

       R
           Recursively remove a path and all its subdirectories (if it
           is a directory). Lines of this type accept shell-style globs
           in place of normal path names. Does not follow symlinks.

       z
           Adjust the access mode, user and group ownership, and restore
           the SELinux security context of a file or directory, if it
           exists. Lines of this type accept shell-style globs in place
           of normal path names. Does not follow symlinks.

       Z
           Recursively set the access mode, user and group ownership,
           and restore the SELinux security context of a file or
           directory if it exists, as well as of its subdirectories and
           the files contained therein (if applicable). Lines of this
           type accept shell-style globs in place of normal path names.
           Does not follow symlinks.

       t
           Set extended attributes, see attr(5) for details. The
           argument field should take one or more assignment expressions
           in the form namespace.attribute=value, for examples see
           below. Lines of this type accept shell-style globs in place
           of normal path names. This can be useful for setting SMACK
           labels. Does not follow symlinks.

           Please note that extended attributes settable with this line
           type are a different concept from the Linux file attributes
           settable with h/H, see below.

           Added in version 218.

       T
           Same as t, but operates recursively.

           Added in version 219.

       h
           Set Linux file/directory attributes. Lines of this type
           accept shell-style globs in place of normal path names.

           The format of the argument field is [+-=][aAcCdDeijPsStTu].
           The prefix + (the default one) causes the attributes to be
           added; - causes the attributes to be removed; = causes the
           attributes to be set exactly as the following letters. The
           letters "aAcCdDeijPsStTu" select the new attributes for the
           files, see chattr(1) for further information.

           Passing only = as argument resets all the file attributes
           listed above. It has to be pointed out that the = prefix
           limits itself to the attributes corresponding to the letters
           listed here. All other attributes will be left untouched.
           Does not follow symlinks.

           Please note that the Linux file attributes settable with this
           line type are a different concept from the extended
           attributes settable with t/T, see above.

       H
           Sames as h, but operates recursively.

           Added in version 220.

       a, a+
           Set POSIX ACLs (access control lists), see acl(5).
           Additionally, if 'X' is used, the execute bit is set only if
           the file is a directory or already has execute permission for
           some user, as mentioned in setfacl(1). If suffixed with +,
           the specified entries will be added to the existing set.
           systemd-tmpfiles(8) will automatically add the required base
           entries for user and group based on the access mode of the
           file, unless base entries already exist or are explicitly
           specified. The mask will be added if not specified explicitly
           or already present. Lines of this type accept shell-style
           globs in place of normal path names. This can be useful for
           allowing additional access to certain files. Does not follow
           symlinks.

           Added in version 219.

       A, A+
           Same as a and a+, but recursive. Does not follow symlinks.

           Added in version 219.

   Type Modifiers
       If the exclamation mark ("!") is used, this line is only safe to
       execute during boot, and can break a running system. Lines
       without the exclamation mark are presumed to be safe to execute
       at any time, e.g. on package upgrades.  systemd-tmpfiles(8) will
       take lines with an exclamation mark only into consideration, if
       the --boot option is given.

       For example:

           # Make sure these are created by default so that nobody else can
           d /tmp/.X11-unix 1777 root root 10d

           # Unlink the X11 lock files
           r! /tmp/.X[0-9]*-lock

       The second line in contrast to the first one would break a
       running system, and will only be executed with --boot.

       If the minus sign ("-") is used, this line failing to run
       successfully during create (and only create) will not cause the
       execution of systemd-tmpfiles to return an error.

       For example:

           # Modify sysfs but don't fail if we are in a container with a read-only /proc
           w- /proc/sys/vm/swappiness - - - - 10

       If the equals sign ("=") is used, the file types of existing
       objects in the specified path are checked, and removed if they do
       not match. This includes any implicitly created parent
       directories (which can be either directories or directory
       symlinks). For example, if there is a FIFO in place of one of the
       parent path components it will be replaced with a directory.

       If the tilde character ("~") is used, the argument (i.e. 6th)
       column is Base64 decoded[1] before use. This modifier is only
       supported on line types that can write file contents, i.e.  f,
       f+, w, +. This is useful for writing arbitrary binary data
       (including newlines and NUL bytes) to files. Note that if this
       switch is used, the argument is not subject to specifier
       expansion, neither before nor after Base64 decoding.

       If the caret character ("^") is used, the argument (i.e. 6th)
       column takes a service credential name to read the argument data
       from. See System and Service Credentials[2] for details about the
       credentials concept. This modifier is only supported on line
       types that can write file contents, i.e.  f, f+, w, w+. This is
       useful for writing arbitrary files with contents sourced from
       elsewhere, including from VM or container managers further up. If
       the specified credential is not set for the systemd-tmpfiles
       service, the line is silently skipped. If "^" and "~" are
       combined Base64 decoding is applied to the credential contents.

       Note that for all line types that result in creation of any kind
       of file node (i.e.  f/F, d/D/v/q/Q, p, L, c/b and C) leading
       directories are implicitly created if needed, owned by root with
       an access mode of 0755. In order to create them with different
       modes or ownership make sure to add appropriate d lines.

   Path
       The file system path specification supports simple specifier
       expansion, see below. The path (after expansion) must be
       absolute.

   Mode
       The file access mode to use when creating this file or directory.
       If omitted or when set to "-", the default is used: 0755 for
       directories, 0644 for all other file objects. For z, Z lines, if
       omitted or when set to "-", the file access mode will not be
       modified. This parameter is ignored for x, r, R, L, t, and a
       lines.

       Optionally, if prefixed with "~", the access mode is masked based
       on the already set access bits for existing file or directories:
       if the existing file has all executable bits unset, all
       executable bits are removed from the new access mode, too.
       Similarly, if all read bits are removed from the old access mode,
       they will be removed from the new access mode too, and if all
       write bits are removed, they will be removed from the new access
       mode too. In addition, the sticky/SUID/SGID bit is removed unless
       applied to a directory. This functionality is particularly useful
       in conjunction with Z.

       By default the access mode of listed inodes is set to the
       specified mode regardless if it is created anew, or already
       existed. Optionally, if prefixed with ":", the configured access
       mode is only applied when creating new inodes, and if the inode
       the line refers to already exists, its access mode is left in
       place unmodified.

   User, Group
       The user and group to use for this file or directory. This may
       either be a numeric ID or a user/group name. If omitted or when
       set to "-", the user and group of the user who invokes
       systemd-tmpfiles(8) is used. For z and Z lines, when omitted or
       when set to "-", the file ownership will not be modified. These
       parameters are ignored for x, r, R, L, t, and a lines.

       This field should generally only reference system users/groups,
       i.e. users/groups that are guaranteed to be resolvable during
       early boot. If this field references users/groups that only
       become resolveable during later boot (i.e. after NIS, LDAP or a
       similar networked directory service become available), execution
       of the operations declared by the line will likely fail. Also see
       Notes on Resolvability of User and Group Names[3] for more
       information on requirements on system user/group definitions.

       By default the ownership of listed inodes is set to the specified
       user/group regardless if it is created anew, or already existed.
       Optionally, if prefixed with ":", the configured user/group
       information is only applied when creating new inodes, and if the
       inode the line refers to already exists, its user/group is left
       in place unmodified.

   Age
       The date field, when set, is used to decide what files to delete
       when cleaning. If a file or directory is older than the current
       time minus the age field, it is deleted. The field format is a
       series of integers each followed by one of the following suffixes
       for the respective time units: s, m or min, h, d, w, ms, and us,
       meaning seconds, minutes, hours, days, weeks, milliseconds, and
       microseconds, respectively. Full names of the time units can be
       used too.

       If multiple integers and units are specified, the time values are
       summed. If an integer is given without a unit, s is assumed.

       When the age is set to zero, the files are cleaned
       unconditionally.

       The age field only applies to lines starting with d, D, e, v, q,
       Q, C, x and X. If omitted or set to "-", no automatic clean-up is
       done.

       If the age field starts with a tilde character "~", clean-up is
       only applied to files and directories one level inside the
       directory specified, but not the files and directories
       immediately inside it.

       The age of a file system entry is determined from its last
       modification timestamp (mtime), its last access timestamp
       (atime), and (except for directories) its last status change
       timestamp (ctime). By default, any of these three (or two) values
       will prevent cleanup if it is more recent than the current time
       minus the age field. To restrict the deletion based on particular
       type of file timestamps, the age-by argument can be used.

       The age-by argument overrides the timestamp types to be used for
       the age check. It can be specified by prefixing the age argument
       with a sequence of characters to specify the timestamp types and
       a colon (":"): "age-by...:cleanup-age". The argument can consist
       of a (A for directories), b (B for directories), c (C for
       directories), or m (M for directories). Those respectively
       indicate access, creation, last status change, and last
       modification time of a file system entry. The lower-case letter
       signifies that the given timestamp type should be considered for
       files, while the upper-case letter signifies that the given
       timestamp type should be considered for directories. See statx(2)
       file timestamp fields for more details about timestamp types.

       If not specified, the age-by field defaults to abcmABM, i.e. by
       default all file timestamps are taken into consideration, with
       the exception of the last status change timestamp (ctime) for
       directories. This is because the aging logic itself will alter
       the ctime whenever it deletes a file inside it. To ensure that
       running the aging logic does not feed back into the next
       iteration of itself, ctime for directories is ignored by default.

       For example:

           # Files created and modified, and directories accessed more than
           # an hour ago in "/tmp/foo/bar", are subject to time-based cleanup.
           d /tmp/foo/bar - - - bmA:1h -

       Note that while the aging algorithm is run an exclusive BSD file
       lock (see flock(2)) is taken on each directory/file the algorithm
       decides to remove. If the aging algorithm finds a lock (shared or
       exclusive) is already taken on some directory/file, it (and
       everything below it) is skipped. Applications may use this to
       temporarily exclude certain directory subtrees from the aging
       algorithm: the applications can take a BSD file lock themselves,
       and as long as they keep it aging of the directory/file and
       everything below it is disabled.

       This behavior can be used to ensure guaranteed cleanup of files
       or directories whose lifetime should be aligned with the process
       that created them by having that process create them in a
       location monitored by systemd-tmpfiles with an age of "0", and
       having the process immediately lock the directory or file before
       using it. Because the BSD lock is process specific, the file is
       guaranteed to be unlocked as soon as the process exits, meaning
       that even if the process crashes, those files and directories
       will be unlocked and cleaned up by systemd-tmpfiles.

   Argument
       For L lines determines the destination path of the symlink. For c
       and b, determines the major/minor of the device node, with major
       and minor formatted as integers, separated by ":", e.g.  "1:3".
       For f, F, and w, the argument may be used to specify a short
       string that is written to the file, suffixed by a newline. For C,
       specifies the source file or directory. For t and T, determines
       extended attributes to be set. For a and A, determines ACL
       attributes to be set. For h and H, determines the file attributes
       to set. Ignored for all other lines.

       This field can contain specifiers, see below.

SPECIFIERS         top

       Specifiers can be used in the "path" and "argument" fields. An
       unknown or unresolvable specifier is treated as invalid
       configuration. The following expansions are understood:

       Table 1. Specifiers available
       ┌───────────┬────────────────────┬────────────────────────┐
       │ Specifier Meaning            Details                │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%a"      │ Architecture       │ A short string         │
       │           │                    │ identifying the        │
       │           │                    │ architecture of        │
       │           │                    │ the local system.      │
       │           │                    │ A string such as       │
       │           │                    │ x86, x86-64 or         │
       │           │                    │ arm64. See the         │
       │           │                    │ architectures          │
       │           │                    │ defined for            │
       │           │                    │ ConditionArchitecture= │
       │           │                    │ in systemd.unit(5)     │
       │           │                    │ for a full list.       │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%A"      │ Operating system   │ The operating system   │
       │           │ image version      │ image version          │
       │           │                    │ identifier of the      │
       │           │                    │ running system, as     │
       │           │                    │ read from the          │
       │           │                    │ IMAGE_VERSION= field   │
       │           │                    │ of /etc/os-release. If │
       │           │                    │ not set, resolves to   │
       │           │                    │ an empty string. See   │
       │           │                    │ os-release(5) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%b"      │ Boot ID            │ The boot ID of the     │
       │           │                    │ running system,        │
       │           │                    │ formatted as string.   │
       │           │                    │ See random(4) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%B"      │ Operating system   │ The operating system   │
       │           │ build ID           │ build identifier of    │
       │           │                    │ the running system, as │
       │           │                    │ read from the          │
       │           │                    │ BUILD_ID= field of     │
       │           │                    │ /etc/os-release. If    │
       │           │                    │ not set, resolves to   │
       │           │                    │ an empty string. See   │
       │           │                    │ os-release(5) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%C"      │ System or user     │ In --user mode, this   │
       │           │ cache directory    │ is the same as         │
       │           │                    │ $XDG_CACHE_HOME, and   │
       │           │                    │ /var/cache otherwise.  │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%g"      │ User group         │ This is the name of    │
       │           │                    │ the group running the  │
       │           │                    │ command. In case of    │
       │           │                    │ the system instance    │
       │           │                    │ this resolves to       │
       │           │                    │ "root".                │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%G"      │ User GID           │ This is the numeric    │
       │           │                    │ GID of the group       │
       │           │                    │ running the command.   │
       │           │                    │ In case of the system  │
       │           │                    │ instance this resolves │
       │           │                    │ to 0.                  │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%h"      │ User home          │ This is the home       │
       │           │ directory          │ directory of the user  │
       │           │                    │ running the command.   │
       │           │                    │ In case of the system  │
       │           │                    │ instance this resolves │
       │           │                    │ to "/root".            │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%H"      │ Host name          │ The hostname of the    │
       │           │                    │ running system.        │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%l"      │ Short host name    │ The hostname of the    │
       │           │                    │ running system,        │
       │           │                    │ truncated at the first │
       │           │                    │ dot to remove any      │
       │           │                    │ domain component.      │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%L"      │ System or user log │ In --user mode, this   │
       │           │ directory          │ is the same as         │
       │           │                    │ $XDG_STATE_HOME with   │
       │           │                    │ /log appended, and     │
       │           │                    │ /var/log otherwise.    │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%m"      │ Machine ID         │ The machine ID of the  │
       │           │                    │ running system,        │
       │           │                    │ formatted as string.   │
       │           │                    │ See machine-id(5) for  │
       │           │                    │ more information.      │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%M"      │ Operating system   │ The operating system   │
       │           │ image identifier   │ image identifier of    │
       │           │                    │ the running system, as │
       │           │                    │ read from the          │
       │           │                    │ IMAGE_ID= field of     │
       │           │                    │ /etc/os-release. If    │
       │           │                    │ not set, resolves to   │
       │           │                    │ an empty string. See   │
       │           │                    │ os-release(5) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%o"      │ Operating system   │ The operating system   │
       │           │ ID                 │ identifier of the      │
       │           │                    │ running system, as     │
       │           │                    │ read from the ID=      │
       │           │                    │ field of               │
       │           │                    │ /etc/os-release. See   │
       │           │                    │ os-release(5) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%S"      │ System or user     │ In --user mode, this   │
       │           │ state directory    │ is the same as         │
       │           │                    │ $XDG_STATE_HOME, and   │
       │           │                    │ /var/lib otherwise.    │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%t"      │ System or user     │ In --user mode, this   │
       │           │ runtime directory  │ is the same            │
       │           │                    │ $XDG_RUNTIME_DIR, and  │
       │           │                    │ /run/ otherwise.       │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%T"      │ Directory for      │ This is either /tmp or │
       │           │ temporary files    │ the path "$TMPDIR",    │
       │           │                    │ "$TEMP" or "$TMP" are  │
       │           │                    │ set to. (Note that the │
       │           │                    │ directory may be       │
       │           │                    │ specified without a    │
       │           │                    │ trailing slash.)       │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%u"      │ User name          │ This is the name of    │
       │           │                    │ the user running the   │
       │           │                    │ command. In case of    │
       │           │                    │ the system instance    │
       │           │                    │ this resolves to       │
       │           │                    │ "root".                │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%U"      │ User UID           │ This is the numeric    │
       │           │                    │ UID of the user        │
       │           │                    │ running the command.   │
       │           │                    │ In case of the system  │
       │           │                    │ instance this resolves │
       │           │                    │ to 0.                  │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%v"      │ Kernel release     │ Identical to uname -r  │
       │           │                    │ output.                │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%V"      │ Directory for      │ This is either         │
       │           │ larger and         │ /var/tmp or the path   │
       │           │ persistent         │ "$TMPDIR", "$TEMP" or  │
       │           │ temporary files    │ "$TMP" are set to.     │
       │           │                    │ (Note that the         │
       │           │                    │ directory may be       │
       │           │                    │ specified without a    │
       │           │                    │ trailing slash.)       │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%w"      │ Operating system   │ The operating system   │
       │           │ version ID         │ version identifier of  │
       │           │                    │ the running system, as │
       │           │                    │ read from the          │
       │           │                    │ VERSION_ID= field of   │
       │           │                    │ /etc/os-release. If    │
       │           │                    │ not set, resolves to   │
       │           │                    │ an empty string. See   │
       │           │                    │ os-release(5) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%W"      │ Operating system   │ The operating system   │
       │           │ variant ID         │ variant identifier of  │
       │           │                    │ the running system, as │
       │           │                    │ read from the          │
       │           │                    │ VARIANT_ID= field of   │
       │           │                    │ /etc/os-release. If    │
       │           │                    │ not set, resolves to   │
       │           │                    │ an empty string. See   │
       │           │                    │ os-release(5) for more │
       │           │                    │ information.           │
       ├───────────┼────────────────────┼────────────────────────┤
       │ "%%"      │ Single percent     │ Use "%%" in place of   │
       │           │ sign               │ "%" to specify a       │
       │           │                    │ single percent sign.   │
       └───────────┴────────────────────┴────────────────────────┘

EXAMPLES         top

       Example 1. Create directories with specific mode and ownership

       screen(1), needs two directories created at boot with specific
       modes and ownership:

           # /usr/lib/tmpfiles.d/screen.conf
           d /run/screens  1777 root screen 10d
           d /run/uscreens 0755 root screen 10d12h

       Contents of /run/screens and /run/uscreens will be cleaned up
       after 10 and 10½ days, respectively.

       Example 2. Create a directory with a SMACK attribute

           D /run/cups - - - -
           t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"

       The directory will be owned by root and have default mode. Its
       contents are not subject to time-based cleanup, but will be
       obliterated when systemd-tmpfiles --remove runs.

       Example 3. Create a directory and prevent its contents from
       cleanup

       abrt(1), needs a directory created at boot with specific mode and
       ownership and its content should be preserved from the automatic
       cleanup applied to the contents of /var/tmp:

           # /usr/lib/tmpfiles.d/tmp.conf
           d /var/tmp 1777 root root 30d

           # /usr/lib/tmpfiles.d/abrt.conf
           d /var/tmp/abrt 0755 abrt abrt -

       Example 4. Apply clean up during boot and based on time

           # /usr/lib/tmpfiles.d/dnf.conf
           r! /var/cache/dnf/*/*/download_lock.pid
           r! /var/cache/dnf/*/*/metadata_lock.pid
           r! /var/lib/dnf/rpmdb_lock.pid
           e  /var/cache/dnf/ - - - 30d

       The lock files will be removed during boot. Any files and
       directories in /var/cache/dnf/ will be removed after they have
       not been accessed in 30 days.

       Example 5. Empty the contents of a cache directory on boot

           # /usr/lib/tmpfiles.d/krb5rcache.conf
           e! /var/cache/krb5rcache - - - 0

       Any files and subdirectories in /var/cache/krb5rcache/ will be
       removed on boot. The directory will not be created.

       Example 6. Provision SSH public key access for root user via
       Credentials in QEMU

           -smbios type=11,value=io.systemd.credential.binary:tmpfiles.extra=$(echo "f~ /root/.ssh/authorized_keys 700 root root - $(ssh-add -L | base64 -w 0)" | base64 -w 0)

       By passing this line to QEMU, the public key of the current user
       will be encoded in base64, added to a tmpfiles.d line that tells
       systemd-tmpfiles to decode it into /root/.ssh/authorized_keys,
       encode that line itself in base64 and pass it as a Credential
       that will be picked up by systemd from SMBIOS on boot.

/RUN/ AND /VAR/RUN/         top

       /var/run/ is a deprecated symlink to /run/, and applications
       should use the latter.  systemd-tmpfiles will warn if /var/run/
       is used.

SEE ALSO         top

       systemd(1), systemd-tmpfiles(8), systemd-delta(1),
       systemd.exec(5), attr(5), getfattr(1), setfattr(1), setfacl(1),
       getfacl(1), chattr(1), btrfs-subvolume(8), btrfs-qgroup(8)

NOTES         top

        1. Base64 decoded
           https://www.rfc-editor.org/rfc/rfc4648.html

        2. System and Service Credentials
           https://systemd.io/CREDENTIALS

        3. Notes on Resolvability of User and Group Names
           https://systemd.io/UIDS-GIDS/#notes-on-resolvability-of-user-and-group-names

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-22.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 255                                                TMPFILES.D(5)

Pages that refer to this page: systemd.exec(5)sysusers.d(5)file-hierarchy(7)systemd.directives(7)systemd.index(7)systemd.system-credentials(7)systemd-pstore.service(8)systemd-tmpfiles(8)