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
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 |
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=
is specified, arguments specified on the
command line are used instead of the configuration file PATH
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 $SYSTEMD_LOG_LEVEL
below).
The following commands are understood:
--create
¶If this command is passed, all files and
directories marked with
f
,
F
,
w
,
d
,
D
,
v
,
p
,
L
,
c
,
b
,
m
in the configuration files are created or written to. Files
and directories marked with
z
,
Z
,
t
,
T
,
a
, and
A
have their ownership, access mode and
security labels set.
--clean
¶If this command is passed, all files and directories with an age parameter configured will be cleaned up.
--remove
¶If this command is passed, the contents of
directories marked with D
or
R
, and files or directories themselves
marked with r
or R
are
removed unless an exclusive or shared BSD lock is taken on them (see flock(2)).
--purge
¶If this option is passed, all files and directories declared for
creation and marked with the "$
" 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.
--user
¶Execute "user" configuration, i.e. tmpfiles.d/
files in user configuration directories.
--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
.
--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.
--dry-run
¶Process the configuration and print what operations would be performed, but do not actually change anything in the file system.
--prefix=path
¶Only apply rules with paths that start with the specified prefix. This option can be specified multiple times.
--exclude-prefix=path
¶Ignore rules with paths that start with the specified prefix. This option can be specified multiple times.
-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.
--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.
--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
Discoverable Partitions
Specification. For further information on supported disk images, see
systemd-nspawn(1)'s
switch of the same name.
Implies -E
.
--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.
--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
¶--version
¶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
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.
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.
$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 [1]). 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.
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.
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.
[1] It is recommended for other tools to set and check $SUDO_UID
as appropriate,
treating it is a common interface.