1FILE-HIERARCHY(7) file-hierarchy FILE-HIERARCHY(7)
2
6 file-hierarchy - File system hierarchy overview
7
9 Operating systems using the systemd(1) system and service manager are
10 organized based on a file system hierarchy inspired by UNIX, more
11 specifically the hierarchy described in the File System Hierarchy[1]
12 specification and hier(7), with various extensions, partially
13 documented in the XDG Base Directory Specification[2] and XDG User
14 Directories[3]. This manual page describes a more generalized, though
15 minimal and modernized subset of these specifications that defines more
16 strictly the suggestions and restrictions systemd makes on the file
17 system hierarchy.
18 Many of the paths described here can be queried with the systemd-
20 path(1) tool.
21
23 /
24 The file system root. Usually writable, but this is not required.
25 Possibly a temporary file system ("tmpfs"). Not shared with other
26 hosts (unless read-only).
27 /boot/
29 The boot partition used for bringing up the system. On EFI systems,
30 this is possibly the EFI System Partition (ESP), also see systemd-
31 gpt-auto-generator(8). This directory is usually strictly local to
32 the host, and should be considered read-only, except when a new
33 kernel or boot loader is installed. This directory only exists on
34 systems that run on physical or emulated hardware that requires
35 boot loaders.
36 /efi/
38 If the boot partition /boot/ is maintained separately from the EFI
39 System Partition (ESP), the latter is mounted here. Tools that need
40 to operate on the EFI system partition should look for it at this
41 mount point first, and fall back to /boot/ — if the former doesn't
42 qualify (for example if it is not a mount point or does not have
43 the correct file system type MSDOS_SUPER_MAGIC).
44 /etc/
46 System-specific configuration. This directory may or may not be
47 read-only. Frequently, this directory is pre-populated with
48 vendor-supplied configuration files, but applications should not
49 make assumptions about this directory being fully populated or
50 populated at all, and should fall back to defaults if configuration
51 is missing.
52 /home/
54 The location for normal user's home directories. Possibly shared
55 with other systems, and never read-only. This directory should only
56 be used for normal users, never for system users. This directory
57 and possibly the directories contained within it might only become
58 available or writable in late boot or even only after user
59 authentication. This directory might be placed on
60 limited-functionality network file systems, hence applications
61 should not assume the full set of file API is available on this
62 directory. Applications should generally not reference this
63 directory directly, but via the per-user $HOME environment
64 variable, or via the home directory field of the user database.
65 /root/
67 The home directory of the root user. The root user's home directory
68 is located outside of /home/ in order to make sure the root user
69 may log in even without /home/ being available and mounted.
70 /srv/
72 The place to store general server payload, managed by the
73 administrator. No restrictions are made how this directory is
74 organized internally. Generally writable, and possibly shared among
75 systems. This directory might become available or writable only
76 very late during boot.
77 /tmp/
79 The place for small temporary files. This directory is usually
80 mounted as a "tmpfs" instance, and should hence not be used for
81 larger files. (Use /var/tmp/ for larger files.) This directory is
82 usually flushed at boot-up. Also, files that are not accessed
83 within a certain time may be automatically deleted.
84 If applications find the environment variable $TMPDIR set, they
86 should use the directory specified in it instead of /tmp/ (see
87 environ(7) and IEEE Std 1003.1[4] for details).
88 Since /tmp/ is accessible to other users of the system, it is
90 essential that files and subdirectories under this directory are
91 only created with mkstemp(3), mkdtemp(3), and similar calls. For
92 more details, see Using /tmp/ and /var/tmp/ Safely[5].
93
95 /run/
96 A "tmpfs" file system for system packages to place runtime data,
97 socket files, and similar. This directory is flushed on boot, and
98 generally writable for privileged programs only. Always writable.
99 /run/log/
101 Runtime system logs. System components may place private logs in
102 this directory. Always writable, even when /var/log/ might not be
103 accessible yet.
104 /run/user/
106 Contains per-user runtime directories, each usually individually
107 mounted "tmpfs" instances. Always writable, flushed at each reboot
108 and when the user logs out. User code should not reference this
109 directory directly, but via the $XDG_RUNTIME_DIR environment
110 variable, as documented in the XDG Base Directory Specification[2].
111
113 /usr/
114 Vendor-supplied operating system resources. Usually read-only, but
115 this is not required. Possibly shared between multiple hosts. This
116 directory should not be modified by the administrator, except when
117 installing or removing vendor-supplied packages.
118 /usr/bin/
120 Binaries and executables for user commands that shall appear in the
121 $PATH search path. It is recommended not to place binaries in this
122 directory that are not useful for invocation from a shell (such as
123 daemon binaries); these should be placed in a subdirectory of
124 /usr/lib/ instead.
125 /usr/include/
127 C and C++ API header files of system libraries.
128 /usr/lib/
130 Static, private vendor data that is compatible with all
131 architectures (though not necessarily architecture-independent).
132 Note that this includes internal executables or other binaries that
133 are not regularly invoked from a shell. Such binaries may be for
134 any architecture supported by the system. Do not place public
135 libraries in this directory, use $libdir (see below), instead.
136 /usr/lib/arch-id/
138 Location for placing dynamic libraries into, also called $libdir.
139 The architecture identifier to use is defined on Multiarch
140 Architecture Specifiers (Tuples)[6] list. Legacy locations of
141 $libdir are /usr/lib/, /usr/lib64/. This directory should not be
142 used for package-specific data, unless this data is
143 architecture-dependent, too. To query $libdir for the primary
144 architecture of the system, invoke:
145 # systemd-path system-library-arch
147 /usr/share/
149 Resources shared between multiple packages, such as documentation,
150 man pages, time zone information, fonts and other resources.
151 Usually, the precise location and format of files stored below this
152 directory is subject to specifications that ensure
153 interoperability.
154 /usr/share/doc/
156 Documentation for the operating system or system packages.
157 /usr/share/factory/etc/
159 Repository for vendor-supplied default configuration files. This
160 directory should be populated with pristine vendor versions of all
161 configuration files that may be placed in /etc/. This is useful to
162 compare the local configuration of a system with vendor defaults
163 and to populate the local configuration with defaults.
164 /usr/share/factory/var/
166 Similar to /usr/share/factory/etc/, but for vendor versions of
167 files in the variable, persistent data directory /var/.
168
170 /var/
171 Persistent, variable system data. Writable during normal system
172 operation. This directory might be pre-populated with
173 vendor-supplied data, but applications should be able to
174 reconstruct necessary files and directories in this subhierarchy
175 should they be missing, as the system might start up without this
176 directory being populated. Persistency is recommended, but
177 optional, to support ephemeral systems. This directory might become
178 available or writable only very late during boot. Components that
179 are required to operate during early boot hence shall not
180 unconditionally rely on this directory.
181 /var/cache/
183 Persistent system cache data. System components may place
184 non-essential data in this directory. Flushing this directory
185 should have no effect on operation of programs, except for
186 increased runtimes necessary to rebuild these caches.
187 /var/lib/
189 Persistent system data. System components may place private data in
190 this directory.
191 /var/log/
193 Persistent system logs. System components may place private logs in
194 this directory, though it is recommended to do most logging via the
195 syslog(3) and sd_journal_print(3) calls.
196 /var/spool/
198 Persistent system spool data, such as printer or mail queues.
199 /var/tmp/
201 The place for larger and persistent temporary files. In contrast to
202 /tmp/, this directory is usually mounted from a persistent physical
203 file system and can thus accept larger files. (Use /tmp/ for small
204 ephemeral files.) This directory is generally not flushed at
205 boot-up, but time-based cleanup of files that have not been
206 accessed for a certain time is applied.
207 If applications find the environment variable $TMPDIR set, they
209 should use the directory specified in it instead of /var/tmp/ (see
210 environ(7) for details).
211 The same security restrictions as with /tmp/ apply: mkstemp(3),
213 mkdtemp(3), and similar calls should be used. For further details
214 about this directory, see Using /tmp/ and /var/tmp/ Safely[5].
215
217 /dev/
218 The root directory for device nodes. Usually, this directory is
219 mounted as a "devtmpfs" instance, but might be of a different type
220 in sandboxed/containerized setups. This directory is managed
221 jointly by the kernel and systemd-udevd(8), and should not be
222 written to by other components. A number of special purpose virtual
223 file systems might be mounted below this directory.
224 /dev/shm/
226 Place for POSIX shared memory segments, as created via shm_open(3).
227 This directory is flushed on boot, and is a "tmpfs" file system.
228 Since all users have write access to this directory, special care
229 should be taken to avoid name clashes and vulnerabilities. For
230 normal users, shared memory segments in this directory are usually
231 deleted when the user logs out. Usually, it is a better idea to use
232 memory mapped files in /run/ (for system programs) or
233 $XDG_RUNTIME_DIR (for user programs) instead of POSIX shared memory
234 segments, since these directories are not world-writable and hence
235 not vulnerable to security-sensitive name clashes.
236 /proc/
238 A virtual kernel file system exposing the process list and other
239 functionality. This file system is mostly an API to interface with
240 the kernel and not a place where normal files may be stored. For
241 details, see proc(5). A number of special purpose virtual file
242 systems might be mounted below this directory.
243 /proc/sys/
245 A hierarchy below /proc/ that exposes a number of kernel tunables.
246 The primary way to configure the settings in this API file tree is
247 via sysctl.d(5) files. In sandboxed/containerized setups, this
248 directory is generally mounted read-only.
249 /sys/
251 A virtual kernel file system exposing discovered devices and other
252 functionality. This file system is mostly an API to interface with
253 the kernel and not a place where normal files may be stored. In
254 sandboxed/containerized setups, this directory is generally mounted
255 read-only. A number of special purpose virtual file systems might
256 be mounted below this directory.
257 /sys/fs/cgroup/
259 A virtual kernel file system exposing process control groups
260 (cgroups). This file system is an API to interface with the kernel
261 and not a place where normal files may be stored. On current
262 systems running in the default "unified" mode, this directory
263 serves as the mount point for the "cgroup2" filesystem, which
264 provides a unified cgroup hierarchy for all resource controllers.
265 On systems with non-default configurations, this directory may
266 instead be a tmpfs filesystem containing mount points for various
267 "cgroup" (v1) resource controllers; in such configurations, if
268 "cgroup2" is mounted it will be mounted on /sys/fs/cgroup/unified/,
269 but cgroup2 will not have resource controllers attached. In
270 sandboxed/containerized setups, this directory may either not exist
271 or may include a subset of functionality.
272
274 /bin/, /sbin/, /usr/sbin/
275 These compatibility symlinks point to /usr/bin/, ensuring that
276 scripts and binaries referencing these legacy paths correctly find
277 their binaries.
278 /lib/
280 This compatibility symlink points to /usr/lib/, ensuring that
281 programs referencing this legacy path correctly find their
282 resources.
283 /lib64/
285 On some architecture ABIs, this compatibility symlink points to
286 $libdir, ensuring that binaries referencing this legacy path
287 correctly find their dynamic loader. This symlink only exists on
288 architectures whose ABI places the dynamic loader in this path.
289 /var/run/
291 This compatibility symlink points to /run/, ensuring that programs
292 referencing this legacy path correctly find their runtime data.
293
295 User applications may want to place files and directories in the user's
296 home directory. They should follow the following basic structure. Note
297 that some of these directories are also standardized (though more
298 weakly) by the XDG Base Directory Specification[2]. Additional
299 locations for high-level user resources are defined by
300 xdg-user-dirs[3].
301 ~/.cache/
303 Persistent user cache data. User programs may place non-essential
304 data in this directory. Flushing this directory should have no
305 effect on operation of programs, except for increased runtimes
306 necessary to rebuild these caches. If an application finds
307 $XDG_CACHE_HOME set, it should use the directory specified in it
308 instead of this directory.
309 ~/.config/
311 Application configuration. When a new user is created, this
312 directory will be empty or not exist at all. Applications should
313 fall back to defaults should their configuration in this directory
314 be missing. If an application finds $XDG_CONFIG_HOME set, it should
315 use the directory specified in it instead of this directory.
316 ~/.local/bin/
318 Executables that shall appear in the user's $PATH search path. It
319 is recommended not to place executables in this directory that are
320 not useful for invocation from a shell; these should be placed in a
321 subdirectory of ~/.local/lib/ instead. Care should be taken when
322 placing architecture-dependent binaries in this place, which might
323 be problematic if the home directory is shared between multiple
324 hosts with different architectures.
325 ~/.local/lib/
327 Static, private vendor data that is compatible with all
328 architectures.
329 ~/.local/lib/arch-id/
331 Location for placing public dynamic libraries. The architecture
332 identifier to use is defined on Multiarch Architecture Specifiers
333 (Tuples)[6] list.
334 ~/.local/share/
336 Resources shared between multiple packages, such as fonts or
337 artwork. Usually, the precise location and format of files stored
338 below this directory is subject to specifications that ensure
339 interoperability. If an application finds $XDG_DATA_HOME set, it
340 should use the directory specified in it instead of this directory.
341 ~/.local/state/
343 Application state. When a new user is created, this directory will
344 be empty or not exist at all. Applications should fall back to
345 defaults should their state in this directory be missing. If an
346 application finds $XDG_STATE_HOME set, it should use the directory
347 specified in it instead of this directory.
348
350 Unprivileged Write Access
351 Unprivileged processes generally lack write access to most of the
352 hierarchy.
353 The exceptions for normal users are /tmp/, /var/tmp/, /dev/shm/, as
355 well as the home directory $HOME (usually found below /home/) and the
356 runtime directory $XDG_RUNTIME_DIR (found below /run/user/) of the
357 user, which are all writable.
358 For unprivileged system processes, only /tmp/, /var/tmp/ and /dev/shm/
360 are writable. If an unprivileged system process needs a private
361 writable directory in /var/ or /run/, it is recommended to either
362 create it before dropping privileges in the daemon code, to create it
363 via tmpfiles.d(5) fragments during boot, or via the StateDirectory= and
364 RuntimeDirectory= directives of service units (see systemd.unit(5) for
365 details).
366 /tmp/, /var/tmp/ and /dev/shm/ should be mounted nosuid and nodev,
368 which means that set-user-id mode and character or block special
369 devices are not interpreted on those file systems. In general it is not
370 possible to mount them noexec, because various programs use those
371 directories for dynamically generated or optimized code, and with that
372 flag those use cases would break. Using this flag is OK on
373 special-purpose installations or systems where all software that may be
374 installed is known and doesn't require such functionality. See the
375 discussion of nosuid/nodev/noexec in mount(8) and PROT_EXEC in mmap(2).
376 Lack of Write Access on Read-Only Systems and during System Recovery
378 As noted above, some systems operate with the /usr and /etc hierarchies
379 mounted read-only, possibly only allowing write access during package
380 upgrades. Other part of the hierarchy are generally mounted read-write
381 (in particular /var and /var/tmp), but may be read-only when the kernel
382 remounts the file system read-only in response to errors, or when the
383 system is booted read-only for recovery purposes. To the extent
384 reasonable, applications should be prepared to execute without write
385 access, so that for example, failure to save non-essential data to
386 /var/cache/ or failure to create a custom log file under /var/log does
387 not prevent the application from running.
388 The /run/ directory is available since the earliest boot and is always
390 writable. It should be used for any runtime data and sockets, so that
391 write access to e.g. /etc or /var is not needed.
392
394 Unix file systems support different types of file nodes, including
395 regular files, directories, symlinks, character and block device nodes,
396 sockets and FIFOs.
397 It is strongly recommended that /dev/ is the only location below which
399 device nodes shall be placed. Similarly, /run/ shall be the only
400 location to place sockets and FIFOs. Regular files, directories and
401 symlinks may be used in all directories.
402
404 Developers of system packages should follow strict rules when placing
405 their files in the file system. The following table lists recommended
406 locations for specific types of files supplied by the vendor.
407 Table 1. System package vendor files locations
409 ┌──────────────────────────┬────────────────────────────┐
410 │Directory │ Purpose │
411 ├──────────────────────────┼────────────────────────────┤
412 │/usr/bin/ │ Package executables that │
413 │ │ shall appear in the $PATH │
414 │ │ executable search path, │
415 │ │ compiled for any of the │
416 │ │ supported architectures │
417 │ │ compatible with the │
418 │ │ operating system. It is │
419 │ │ not recommended to place │
420 │ │ internal binaries or │
421 │ │ binaries that are not │
422 │ │ commonly invoked from the │
423 │ │ shell in this directory, │
424 │ │ such as daemon binaries. │
425 │ │ As this directory is │
426 │ │ shared with most other │
427 │ │ packages of the system, │
428 │ │ special care should be │
429 │ │ taken to pick unique names │
430 │ │ for files placed here, │
431 │ │ that are unlikely to clash │
432 │ │ with other package's │
433 │ │ files. │
434 ├──────────────────────────┼────────────────────────────┤
435 │/usr/lib/arch-id/ │ Public shared libraries of │
436 │ │ the package. As above, be │
437 │ │ careful with using too │
438 │ │ generic names, and pick │
439 │ │ unique names for your │
440 │ │ libraries to place here to │
441 │ │ avoid name clashes. │
442 ├──────────────────────────┼────────────────────────────┤
443 │/usr/lib/package/ │ Private static vendor │
444 │ │ resources of the package, │
445 │ │ including private binaries │
446 │ │ and libraries, or any │
447 │ │ other kind of read-only │
448 │ │ vendor data. │
449 ├──────────────────────────┼────────────────────────────┤
450 │/usr/lib/arch-id/package/ │ Private other vendor │
451 │ │ resources of the package │
452 │ │ that are │
453 │ │ architecture-specific and │
454 │ │ cannot be shared between │
455 │ │ architectures. Note that │
456 │ │ this generally does not │
457 │ │ include private │
458 │ │ executables since binaries │
459 │ │ of a specific architecture │
460 │ │ may be freely invoked from │
461 │ │ any other supported system │
462 │ │ architecture. │
463 ├──────────────────────────┼────────────────────────────┤
464 │/usr/include/package/ │ Public C/C++ APIs of │
465 │ │ public shared libraries of │
466 │ │ the package. │
467 └──────────────────────────┴────────────────────────────┘
468 Additional static vendor files may be installed in the /usr/share/
470 hierarchy to the locations defined by the various relevant
471 specifications.
472 The following directories shall be used by the package for local
474 configuration and files created during runtime:
475 Table 2. System package variable files locations
477 ┌────────────────────┬────────────────────────────┐
478 │Directory │ Purpose │
479 ├────────────────────┼────────────────────────────┤
480 │/etc/package/ │ System-specific │
481 │ │ configuration for the │
482 │ │ package. It is recommended │
483 │ │ to default to safe │
484 │ │ fallbacks if this │
485 │ │ configuration is missing, │
486 │ │ if this is possible. │
487 │ │ Alternatively, a │
488 │ │ tmpfiles.d(5) fragment may │
489 │ │ be used to copy or symlink │
490 │ │ the necessary files and │
491 │ │ directories from │
492 │ │ /usr/share/factory/ during │
493 │ │ boot, via the "L" or "C" │
494 │ │ directives. │
495 ├────────────────────┼────────────────────────────┤
496 │/run/package/ │ Runtime data for the │
497 │ │ package. Packages must be │
498 │ │ able to create the │
499 │ │ necessary subdirectories │
500 │ │ in this tree on their own, │
501 │ │ since the directory is │
502 │ │ flushed automatically on │
503 │ │ boot. Alternatively, a │
504 │ │ tmpfiles.d(5) fragment may │
505 │ │ be used to create the │
506 │ │ necessary directories │
507 │ │ during boot, or the │
508 │ │ RuntimeDirectory= │
509 │ │ directive of service units │
510 │ │ may be used to create them │
511 │ │ at service startup (see │
512 │ │ systemd.unit(5) for │
513 │ │ details). │
514 ├────────────────────┼────────────────────────────┤
515 │/run/log/package/ │ Runtime log data for the │
516 │ │ package. As above, the │
517 │ │ package needs to make sure │
518 │ │ to create this directory │
519 │ │ if necessary, as it will │
520 │ │ be flushed on every boot. │
521 ├────────────────────┼────────────────────────────┤
522 │/var/cache/package/ │ Persistent cache data of │
523 │ │ the package. If this │
524 │ │ directory is flushed, the │
525 │ │ application should work │
526 │ │ correctly on next │
527 │ │ invocation, though │
528 │ │ possibly slowed down due │
529 │ │ to the need to rebuild any │
530 │ │ local cache files. The │
531 │ │ application must be │
532 │ │ capable of recreating this │
533 │ │ directory should it be │
534 │ │ missing and necessary. To │
535 │ │ create an empty directory, │
536 │ │ a tmpfiles.d(5) fragment │
537 │ │ or the CacheDirectory= │
538 │ │ directive of service units │
539 │ │ (see systemd.unit(5)) may │
540 │ │ be used. │
541 ├────────────────────┼────────────────────────────┤
542 │/var/lib/package/ │ Persistent private data of │
543 │ │ the package. This is the │
544 │ │ primary place to put │
545 │ │ persistent data that does │
546 │ │ not fall into the other │
547 │ │ categories listed. │
548 │ │ Packages should be able to │
549 │ │ create the necessary │
550 │ │ subdirectories in this │
551 │ │ tree on their own, since │
552 │ │ the directory might be │
553 │ │ missing on boot. To create │
554 │ │ an empty directory, a │
555 │ │ tmpfiles.d(5) fragment or │
556 │ │ the StateDirectory= │
557 │ │ directive of service units │
558 │ │ (see systemd.unit(5)) may │
559 │ │ be used. │
560 ├────────────────────┼────────────────────────────┤
561 │/var/log/package/ │ Persistent log data of the │
562 │ │ package. As above, the │
563 │ │ package should make sure │
564 │ │ to create this directory │
565 │ │ if necessary, possibly │
566 │ │ using tmpfiles.d(5) or │
567 │ │ LogsDirectory= (see │
568 │ │ systemd.exec(5)), as it │
569 │ │ might be missing. │
570 ├────────────────────┼────────────────────────────┤
571 │/var/spool/package/ │ Persistent spool/queue │
572 │ │ data of the package. As │
573 │ │ above, the package should │
574 │ │ make sure to create this │
575 │ │ directory if necessary, as │
576 │ │ it might be missing. │
577 └────────────────────┴────────────────────────────┘
578
580 Programs running in user context should follow strict rules when
581 placing their own files in the user's home directory. The following
582 table lists recommended locations in the home directory for specific
583 types of files supplied by the vendor if the application is installed
584 in the home directory. (User applications installed system-wide are
585 covered by the rules outlined above for vendor files.)
586 Table 3. Vendor package file locations under the home directory of the
588 user
589 ┌──────────────────────────────┬────────────────────────────┐
590 │Directory │ Purpose │
591 ├──────────────────────────────┼────────────────────────────┤
592 │~/.local/bin/ │ Package executables that │
593 │ │ shall appear in the $PATH │
594 │ │ executable search path. It │
595 │ │ is not recommended to │
596 │ │ place internal executables │
597 │ │ or executables that are │
598 │ │ not commonly invoked from │
599 │ │ the shell in this │
600 │ │ directory, such as daemon │
601 │ │ executables. As this │
602 │ │ directory is shared with │
603 │ │ most other packages of the │
604 │ │ user, special care should │
605 │ │ be taken to pick unique │
606 │ │ names for files placed │
607 │ │ here, that are unlikely to │
608 │ │ clash with other package's │
609 │ │ files. │
610 ├──────────────────────────────┼────────────────────────────┤
611 │~/.local/lib/arch-id/ │ Public shared libraries of │
612 │ │ the package. As above, be │
613 │ │ careful with using overly │
614 │ │ generic names, and pick │
615 │ │ unique names for your │
616 │ │ libraries to place here to │
617 │ │ avoid name clashes. │
618 ├──────────────────────────────┼────────────────────────────┤
619 │~/.local/lib/package/ │ Private, static vendor │
620 │ │ resources of the package, │
621 │ │ compatible with any │
622 │ │ architecture, or any other │
623 │ │ kind of read-only vendor │
624 │ │ data. │
625 ├──────────────────────────────┼────────────────────────────┤
626 │~/.local/lib/arch-id/package/ │ Private other vendor │
627 │ │ resources of the package │
628 │ │ that are │
629 │ │ architecture-specific and │
630 │ │ cannot be shared between │
631 │ │ architectures. │
632 └──────────────────────────────┴────────────────────────────┘
633 Additional static vendor files may be installed in the ~/.local/share/
635 hierarchy, mirroring the subdirectories specified in the section
636 "Vendor-supplied operating system resources" above.
637 The following directories shall be used by the package for per-user
639 local configuration and files created during runtime:
640 Table 4. User package variable file locations
642 ┌──────────────────────────┬────────────────────────────┐
643 │Directory │ Purpose │
644 ├──────────────────────────┼────────────────────────────┤
645 │~/.config/package/ │ User-specific │
646 │ │ configuration and state │
647 │ │ for the package. It is │
648 │ │ required to default to │
649 │ │ safe fallbacks if this │
650 │ │ configuration is missing. │
651 ├──────────────────────────┼────────────────────────────┤
652 │$XDG_RUNTIME_DIR/package/ │ User runtime data for the │
653 │ │ package. │
654 ├──────────────────────────┼────────────────────────────┤
655 │~/.cache/package/ │ Persistent cache data of │
656 │ │ the package. If this │
657 │ │ directory is flushed, the │
658 │ │ application should work │
659 │ │ correctly on next │
660 │ │ invocation, though │
661 │ │ possibly slowed down due │
662 │ │ to the need to rebuild any │
663 │ │ local cache files. The │
664 │ │ application must be │
665 │ │ capable of recreating this │
666 │ │ directory should it be │
667 │ │ missing and necessary. │
668 └──────────────────────────┴────────────────────────────┘
669
671 systemd(1), hier(7), systemd-path(1), systemd-gpt-auto-generator(8),
672 sysctl.d(5), tmpfiles.d(5), pkg-config(1), systemd.unit(5)
673
675 1. File System Hierarchy
676 http://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html
677 2. XDG Base Directory Specification
679 https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
680 3. XDG User Directories
682 https://www.freedesktop.org/wiki/Software/xdg-user-dirs
683 4. IEEE Std 1003.1
685 http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03
686 5. Using /tmp/ and /var/tmp/ Safely
688 https://systemd.io/TEMPORARY_DIRECTORIES
689 6. Multiarch Architecture Specifiers (Tuples)
691 https://wiki.debian.org/Multiarch/Tuples
692systemd 254 FILE-HIERARCHY(7)