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 — Creates, deletes and cleans up volatile and temporary 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). It must
    be invoked with one or more options --create, --remove, and
    --clean, to select the respective subset of operations.
By default, directives from all configuration files are applied. When invoked with
    --replace=, arguments specified on the command line are
    used instead of the configuration file PATHPATH. Otherwise, if one or more
    absolute filenames are passed on the command line, only the directives in these files are applied. If
    "-" is specified instead of a filename, directives are read from standard input. If only
    the basename of a configuration file is specified, all configuration directories as specified in
    tmpfiles.d(5) are
    searched for a matching file and the file found that has the highest priority is executed.
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 options are understood:
--create¶If this option 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 option is passed, all files and directories with an age parameter configured will be cleaned up.
--remove¶If this option 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)).
        
--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.
--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). 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.
$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:
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.