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Manual: systemd-tmpfiles

SYSTEMD-TMPFILES(8) systemd-tmpfiles SYSTEMD-TMPFILES(8)

NAME
systemd-tmpfiles, systemd-tmpfiles-setup.service, systemd-tmpfiles-setup-dev-early.service, systemd-
tmpfiles-setup-dev.service, systemd-tmpfiles-clean.service, systemd-tmpfiles-clean.timer - Create,
delete, and clean up files and directories

SYNOPSIS

systemd-tmpfiles [OPTIONS...] [CONFIGFILE...]

System units:
systemd-tmpfiles-setup.service
systemd-tmpfiles-setup-dev-early.service
systemd-tmpfiles-setup-dev.service
systemd-tmpfiles-clean.service
systemd-tmpfiles-clean.timer

User units:
systemd-tmpfiles-setup.service
systemd-tmpfiles-clean.service
systemd-tmpfiles-clean.timer

DESCRIPTION
systemd-tmpfiles creates, deletes, and cleans up files and directories, using the configuration file
format and location specified in tmpfiles.d(5). Historically, it was designed to manage volatile and
temporary files, as the name suggests, but it provides generic file management functionality and can
be used to manage any kind of files. It must be invoked with one or more commands --create, --remove,
and --clean, to select the respective subset of operations.

If invoked with no arguments, directives from the configuration files found in the directories
specified by tmpfiles.d(5) are executed. When invoked with positional arguments, if option
--replace=PATH is specified, arguments specified on the command line are used instead of the
configuration file PATH. Otherwise, just the configuration specified by the command line arguments is
executed. If the string "-" is specified instead of a filename, the configuration is read from
standard input. If the argument is a file name (without any slashes), all configuration directories
are searched for a matching file and the file found that has the highest priority is executed. If the
argument is a path, that file is used directly without searching the configuration directories for
any other matching file.

System services (systemd-tmpfiles-setup.service, systemd-tmpfiles-setup-dev-early.service,
systemd-tmpfiles-setup-dev.service, systemd-tmpfiles-clean.service) invoke systemd-tmpfiles to create
system files and to perform system wide cleanup. Those services read administrator-controlled
configuration files in tmpfiles.d/ directories. User services (systemd-tmpfiles-setup.service,
systemd-tmpfiles-clean.service) also invoke systemd-tmpfiles, but it reads a separate set of files,
which includes user-controlled files under ~/.config/user-tmpfiles.d/ and
~/.local/share/user-tmpfiles.d/, and administrator-controlled files under
/usr/share/user-tmpfiles.d/. Users may use this to create and clean up files under their control, but
the system instance performs global cleanup and is not influenced by user configuration. Note that
this means a time-based cleanup configured in the system instance, such as the one typically
configured for /tmp/, will thus also affect files created by the user instance if they are placed in
/tmp/, even if the user instance's time-based cleanup is turned off.

To re-apply settings after configuration has been modified, simply restart
systemd-tmpfiles-clean.service, which will apply any settings which can be safely executed at
runtime. To debug systemd-tmpfiles, it may be useful to invoke it directly from the command line with
increased log level (see $SYSTEMD_LOG_LEVEL below).

COMMANDS AND OPTIONS
The following commands are understood:

--create
If this command is passed, all files and directories marked with f, F, w, d, D, v, p, L, c, b, m
in the configuration files are created or written to. Files and directories marked with z, Z, t,
T, a, and A have their ownership, access mode and security labels set.

--clean
If this command is passed, all files and directories with an age parameter configured will be
cleaned up.

--remove
If this command is passed, the contents of directories marked with D or R, and files or
directories themselves marked with r or R are removed unless an exclusive or shared BSD lock is
taken on them (see flock(2)).

--purge
If this option is passed, all files and directories declared for creation and marked with the "$"
character by the tmpfiles.d/ files specified on the command line will be deleted. Specifically,
this acts on all files and directories marked with f, F, d, D, v, q, Q, p, L, c, b, C, w, e. If
this switch is used at least one tmpfiles.d/ file (or - for standard input) must be specified on
the command line or the invocation will be refused, for safety reasons (as otherwise much of the
installed system files might be removed).

The primary usecase for this option is to automatically remove files and directories that
originally have been created on behalf of an installed package at package removal time.

It is recommended to first run this command in combination with --dry-run (see below) to verify
which files and directories will be deleted.

Warning! This is usually not the command you want! In most cases --remove is what you are
looking for.

Added in version 256.

--user
Execute "user" configuration, i.e. tmpfiles.d/ files in user configuration directories.

Added in version 236.

--boot
Also execute lines with an exclamation mark. Lines that are not safe to be executed on a running
system may be marked in this way. systemd-tmpfiles is executed in early boot with --boot
specified and will execute those lines. When invoked again later, it should be called without
--boot.

Added in version 209.

--graceful
Ignore configuration lines pertaining to unknown users or groups. This option is intended to be
used in early boot before all users or groups have been created.

Added in version 254.

--dry-run
Process the configuration and print what operations would be performed, but do not actually
change anything in the file system.

Added in version 256.

--prefix=path
Only apply rules with paths that start with the specified prefix. This option can be specified
multiple times.

Added in version 212.

--exclude-prefix=path
Ignore rules with paths that start with the specified prefix. This option can be specified
multiple times.

Added in version 207.

-E
A shortcut for "--exclude-prefix=/dev --exclude-prefix=/proc --exclude-prefix=/run
--exclude-prefix=/sys", i.e. exclude the hierarchies typically backed by virtual or memory file
systems. This is useful in combination with --root=, if the specified directory tree contains an
OS tree without these virtual/memory file systems mounted in, as it is typically not desirable to
create any files and directories below these subdirectories if they are supposed to be
overmounted during runtime.

Added in version 247.

--root=root
Takes a directory path as an argument. All paths will be prefixed with the given alternate root
path, including config search paths.

When this option is used, the libc Name Service Switch (NSS) is bypassed for resolving users and
groups. Instead the files /etc/passwd and /etc/group inside the alternate root are read directly.
This means that users/groups not listed in these files will not be resolved, i.e. LDAP NIS and
other complex databases are not considered.

Consider combining this with -E to ensure the invocation does not create files or directories
below mount points in the OS image operated on that are typically overmounted during runtime.

Added in version 212.

--image=image
Takes a path to a disk image file or block device node. If specified all operations are applied
to file system in the indicated disk image. This is similar to --root= but operates on file
systems stored in disk images or block devices. The disk image should either contain just a file
system or a set of file systems within a GPT partition table, following the UAPI.2 Discoverable
Partitions Specification[1]. For further information on supported disk images, see systemd-
nspawn(1)'s switch of the same name.

Implies -E.

Added in version 247.

--image-policy=policy
Takes an image policy string as argument, as per systemd.image-policy(7). The policy is enforced
when operating on the disk image specified via --image=, see above. If not specified, defaults to
the "*" policy, i.e. all recognized file systems in the image are used.

--replace=PATH
When this option is given, one or more positional arguments must be specified. All configuration
files found in the directories listed in tmpfiles.d(5) will be read, and the configuration given
on the command line will be handled instead of and with the same priority as the configuration
file PATH.

This option is intended to be used when package installation scripts are running and files
belonging to that package are not yet available on disk, so their contents must be given on the
command line, but the admin configuration might already exist and should be given higher
priority.

Added in version 238.

--cat-config
Copy the contents of config files to standard output. Before each file, the filename is printed
as a comment.

--tldr
Copy the contents of config files to standard output. Only the "interesting" parts of the
configuration files are printed, comments and empty lines are skipped. Before each file, the
filename is printed as a comment.

--no-pager
Do not pipe output into a pager.

-h, --help
Print a short help text and exit.

--version
Print a short version string and exit.

It is possible to combine --create, --clean, and --remove in one invocation (in which case removal
and cleanup are executed before creation of new files). For example, during boot the following
command line is executed to ensure that all temporary and volatile directories are removed and
created according to the configuration file:

systemd-tmpfiles --remove --create

CREDENTIALS
systemd-tmpfiles supports the service credentials logic as implemented by
ImportCredential=/LoadCredential=/SetCredential= (see systemd.exec(5) for details). The following
credentials are used when passed in:

tmpfiles.extra
The contents of this credential may contain additional lines to operate on. The credential
contents should follow the same format as any other tmpfiles.d/ drop-in configuration file. If
this credential is passed it is processed after all of the drop-in files read from the file
system. The lines in the credential can hence augment existing lines of the OS, but not override
them.

Added in version 252.

Note that by default the systemd-tmpfiles-setup.service unit file (and related unit files) is set up
to inherit the "tmpfiles.extra" credential from the service manager.

ENVIRONMENT
$SYSTEMD_LOG_LEVEL
The maximum log level of emitted messages (messages with a higher log level, i.e. less important
ones, will be suppressed). Takes a comma-separated list of values. A value may be either one of
(in order of decreasing importance) emerg, alert, crit, err, warning, notice, info, debug, or an
integer in the range 0...7. See syslog(3) for more information. Each value may optionally be
prefixed with one of console, syslog, kmsg or journal followed by a colon to set the maximum log
level for that specific log target (e.g. SYSTEMD_LOG_LEVEL=debug,console:info specifies to log
at debug level except when logging to the console which should be at info level). Note that the
global maximum log level takes priority over any per target maximum log levels.

$SYSTEMD_LOG_COLOR
A boolean. If true, messages written to the tty will be colored according to priority.

This setting is only useful when messages are written directly to the terminal, because
journalctl(1) and other tools that display logs will color messages based on the log level on
their own.

$SYSTEMD_LOG_TIME
A boolean. If true, console log messages will be prefixed with a timestamp.

This setting is only useful when messages are written directly to the terminal or a file, because
journalctl(1) and other tools that display logs will attach timestamps based on the entry
metadata on their own.

$SYSTEMD_LOG_LOCATION
A boolean. If true, messages will be prefixed with a filename and line number in the source code
where the message originates.

Note that the log location is often attached as metadata to journal entries anyway. Including it
directly in the message text can nevertheless be convenient when debugging programs.

$SYSTEMD_LOG_TARGET
The destination for log messages. One of console (log to the attached tty), console-prefixed (log
to the attached tty but with prefixes encoding the log level and "facility", see syslog(3), kmsg
(log to the kernel circular log buffer), journal (log to the journal), journal-or-kmsg (log to
the journal if available, and to kmsg otherwise), auto (determine the appropriate log target
automatically, the default), null (disable log output).

$SYSTEMD_PAGER, $PAGER
Pager to use when --no-pager is not given. $SYSTEMD_PAGER is used if set; otherwise $PAGER is
used. If neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known pager implementations is
tried in turn, including less(1) and more(1), until one is found. If no pager implementation is
discovered, no pager is invoked. Setting those environment variables to an empty string or the
value "cat" is equivalent to passing --no-pager.

Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER and $PAGER can only be used to disable
the pager (with "cat" or ""), and are otherwise ignored.

$SYSTEMD_LESS
Override the options passed to less (by default "FRSXMK").

Users might want to change two options in particular:

K
This option instructs the pager to exit immediately when Ctrl+C is pressed. To allow less to
handle Ctrl+C itself to switch back to the pager command prompt, unset this option.

If the value of $SYSTEMD_LESS does not include "K", and the pager that is invoked is less,
Ctrl+C will be ignored by the executable, and needs to be handled by the pager.

X
This option instructs the pager to not send termcap initialization and deinitialization
strings to the terminal. It is set by default to allow command output to remain visible in
the terminal even after the pager exits. Nevertheless, this prevents some pager functionality
from working, in particular paged output cannot be scrolled with the mouse.

Note that setting the regular $LESS environment variable has no effect for less invocations by
systemd tools.

See less(1) for more discussion.

$SYSTEMD_LESSCHARSET
Override the charset passed to less (by default "utf-8", if the invoking terminal is determined
to be UTF-8 compatible).

Note that setting the regular $LESSCHARSET environment variable has no effect for less
invocations by systemd tools.

$SYSTEMD_PAGERSECURE
Common pager commands like less(1), in addition to "paging", i.e. scrolling through the output,
support opening of or writing to other files and running arbitrary shell commands. When commands
are invoked with elevated privileges, for example under sudo(8) or pkexec(1), the pager becomes a
security boundary. Care must be taken that only programs with strictly limited functionality are
used as pagers, and unintended interactive features like opening or creation of new files or
starting of subprocesses are not allowed. "Secure mode" for the pager may be enabled as described
below, if the pager supports that (most pagers are not written in a way that takes this into
consideration). It is recommended to either explicitly enable "secure mode" or to completely
disable the pager using --no-pager or PAGER=cat when allowing untrusted users to execute commands
with elevated privileges.

This option takes a boolean argument. When set to true, the "secure mode" of the pager is
enabled. In "secure mode", LESSSECURE=1 will be set when invoking the pager, which instructs the
pager to disable commands that open or create new files or start new subprocesses. Currently only
less(1) is known to understand this variable and implement "secure mode".

When set to false, no limitation is placed on the pager. Setting SYSTEMD_PAGERSECURE=0 or not
removing it from the inherited environment may allow the user to invoke arbitrary commands.

When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to automatically figure out if
"secure mode" should be enabled and whether the pager supports it. "Secure mode" is enabled if
the effective UID is not the same as the owner of the login session, see geteuid(2) and
sd_pid_get_owner_uid(3), or when running under sudo(8) or similar tools ($SUDO_UID is set [2]).
In those cases, SYSTEMD_PAGERSECURE=1 will be set and pagers which are not known to implement
"secure mode" will not be used at all. Note that this autodetection only covers the most common
mechanisms to elevate privileges and is intended as convenience. It is recommended to explicitly
set $SYSTEMD_PAGERSECURE or disable the pager.

Note that if the $SYSTEMD_PAGER or $PAGER variables are to be honoured, other than to disable the
pager, $SYSTEMD_PAGERSECURE must be set too.

$SYSTEMD_COLORS
Takes a boolean argument. When true, systemd and related utilities will use colors in their
output, otherwise the output will be monochrome. Additionally, the variable can take one of the
following special values: "16", "256" to restrict the use of colors to the base 16 or 256 ANSI
colors, respectively. This can be specified to override the automatic decision based on $TERM and
what the console is connected to.

$SYSTEMD_URLIFY
The value must be a boolean. Controls whether clickable links should be generated in the output
for terminal emulators supporting this. This can be specified to override the decision that
systemd makes based on $TERM and other conditions.

UNPRIVILEGED --CLEANUP OPERATION
systemd-tmpfiles tries to avoid changing the access and modification times on the directories it
accesses, which requires CAP_FOWNER privileges. When running as non-root, directories which are
checked for files to clean up will have their access time bumped, which might prevent their cleanup.

EXIT STATUS
On success, 0 is returned. If the configuration was syntactically invalid (syntax errors, missing
arguments, ...), so some lines had to be ignored, but no other errors occurred, 65 is returned
(EX_DATAERR from /usr/include/sysexits.h). If the configuration was syntactically valid, but could
not be executed (lack of permissions, creation of files in missing directories, invalid contents when
writing to /sys/ values, ...), 73 is returned (EX_CANTCREAT from /usr/include/sysexits.h). Otherwise,
1 is returned (EXIT_FAILURE from /usr/include/stdlib.h).

Note: when creating items, if the target already exists, but is of the wrong type or otherwise does
not match the requested state, and forced operation has not been requested with "+", a message is
emitted, but the failure is otherwise ignored.

Manual: systemd-tmpfiles

Related Commands: