SYSTEMD-TMPFILES(8)

📦
version 262.1 · 16 versions
, in arch rolling

💖 SYSTEMD-TMPFILES(8) 💖

okay bestie, welcome to the SYSTEMD-TMPFILES(8) manual page. This is the one about systemd-tmpfiles and its service/timer besties. It's giving file management, no cap. ✨

✨ 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 💅

okay so 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.

  • -n, --dry-run — Process the configuration and print what operations would be performed, but do not actually change anything in the file system. The short option -n was added in version 262.

Added in version 256.

  • --inline — Treat each positional argument as a separate configuration line instead of a file name.

Added in version 261.

  • --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.

Note that this is not a sandboxing or security feature. tmpfiles.d(5) definitions are potentially not processed in a hermetic fashion to the specified root.

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 🔐

ok so systemd-tmpfiles is fully in on the service credentials thing — the whole ImportCredential= / LoadCredential= / SetCredential= situation (peep systemd.exec(5) for the deets). When these get passed in, here's what it does with them:

  • tmpfiles.extra — the contents of this credential can hold extra lines to operate on. Format? Same as any other tmpfiles.d/ drop-in config file, no notes. If this credential is passed, it gets processed after all the drop-in files read off the filesystem. So basically the lines in the credential can augment existing lines of the OS — but they can't override them. bestie cannot simply edit the OS's homework, only add to it 💅

Added in version 252.

heads up: by default the systemd-tmpfiles-setup.service unit file (and its related unit files) is set up to inherit the "tmpfiles.extra" credential from the service manager. so it just... comes with it ✨

🌸 ENVIRONMENT 🌸

  • $SYSTEMD_LOG_LEVEL — the max log level of emitted messages (anything higher than that, i.e. less important, gets suppressed, sorry). Takes a comma-separated list of values. Each value is 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. Each value can optionally be prefixed with one of console, syslog, kmsg or journal followed by a colon, which sets the max log level for that specific log target only (like SYSTEMD_LOG_LEVEL=debug,console:info — meaning log at debug level, except when logging to the console, which should be at info level). Note that the global max log level takes priority over any per-target max log levels. the way that the global one just wins 😤
  • $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. they do not need ur help, they got it

  • $SYSTEMD_LOG_TIME — a boolean. If true, console log messages get prefixed with a timestamp. ⏰

Only useful when messages go directly to the terminal or a file, because journalctl(1) and other log-displaying tools attach timestamps based on the entry metadata on their own.

  • $SYSTEMD_LOG_LOCATION — a boolean. If true, messages get prefixed with a filename and line number in the source code where the message originates. iykyk 🐛

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 — where the log messages go. 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 — the pager to use when --no-pager isn't given. $SYSTEMD_PAGER is used if it's set; otherwise $PAGER. If neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known pager implementations gets tried in turn, including less(1) and more(1), until one is found. If no pager implementation is discovered, no pager is invoked at all. Setting those environment variables to an empty string or to 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. rude but true 😭
  • $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 let less handle Ctrl+C itself — so it switches back to the pager command prompt — unset this option.

If the value of $SYSTEMD_LESS does not include "K", and the pager 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's set by default so that command output stays 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. 🖱️ rip

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 — okay bestie this one is the serious one, stay with me. Common pager commands like less(1), on top of "paging" (i.e. scrolling through the output), support opening 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 that unintended interactive features like opening or creating new files or starting 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's 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. 🔥 do not skip this part

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's 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, or a special value. By default (unset), systemd and related utilities will use colors in their output if possible. If $COLORTERM is set to "truecolor" or "24bit", 24-bit colors will be enabled, 256 colors otherwise, unless $NO_COLOR or $TERM indicates colors are disabled. 🎨
    • true — same as unset, except that $NO_COLOR is ignored.
    • false — the output will be monochrome.
    • "16", "256", "24bit" — always use the base 16 ANSI colors, 256 colors, or 24 bit color, respectively.
    • "auto-16", "auto-256", "auto-24bit" — use the given quantity of colours, subject to $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 😭

so 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. it's giving catch-22 fr fr 💀

✨ 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. 👀 not a full on fail, just a lil note

👑 SEE ALSO 👑

systemd(1), tmpfiles.d(5)

📎 NOTES 📎

  1. UAPI.2 Discoverable Partitions Specification https://uapi-group.org/specifications/specs/discoverable_partitions_specification
  2. It is recommended for other tools to set and check $SUDO_UID as appropriate, treating it is a common interface.

and that's the whole thing bestie, you ate 🫶 this was systemd 262.1, SYSTEMD-TMPFILES(8), and the page is dated alongside that version — go forth and tmpfiles, you absolute icon 💅🎀🦋

📦 where this page comes from
  • arch rolling: systemd 262.1-1 · LGPL-2.1-or-later AND CC0-1.0 AND GPL-2.0-or-later AND MIT-0
  • 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms