man7/hier.7

   1 .\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)
   2 .\"
   3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   4 .\"
   5 .\" Modified Sun Jul 25 11:05:58 1993 by Rik Faith (faith@cs.unc.edu)
   6 .\" Modified Sat Feb 10 16:18:03 1996 by Urs Thuermann (urs@isnogud.escape.de)
   7 .\" Modified Mon Jun 16 20:02:00 1997 by Nicolás Lichtmaier <nick@debian.org>
   8 .\" Modified Mon Feb  6 16:41:00 1999 by Nicolás Lichtmaier <nick@debian.org>
   9 .\" Modified Tue Feb  8 16:46:45 2000 by Chris Pepper <pepper@tgg.com>
  10 .\" Modified Fri Sep  7 20:32:45 2001 by Tammy Fox <tfox@redhat.com>
  11 .TH hier 7 (date) "Linux man-pages (unreleased)"
  12 .SH NAME
  13 hier \- description of the filesystem hierarchy
  14 .SH DESCRIPTION
  15 A typical Linux system has, among others, the following directories:
  16 .TP
  17 .I /
  18 This is the root directory.
  19 This is where the whole tree starts.
  20 .TP
  21 .I /bin
  22 This directory contains executable programs which are needed in
  23 single user mode and to bring the system up or repair it.
  24 .TP
  25 .I /boot
  26 Contains static files for the boot loader.
  27 This directory holds only
  28 the files which are needed during the boot process.
  29 The map installer
  30 and configuration files should go to
  31 .I /sbin
  32 and
  33 .IR /etc .
  34 The operating system kernel (initrd for example) must be located in either
  35 .I /
  36 or
  37 .IR /boot .
  38 .TP
  39 .I /dev
  40 Special or device files, which refer to physical devices.
  41 See
  42 .BR mknod (1).
  43 .TP
  44 .I /etc
  45 Contains configuration files which are local to the machine.
  46 Some
  47 larger software packages, like X11, can have their own subdirectories
  48 below
  49 .IR /etc .
  50 Site-wide configuration files may be placed here or in
  51 .IR /usr/etc .
  52 Nevertheless, programs should always look for these files in
  53 .I /etc
  54 and you may have links for these files to
  55 .IR /usr/etc .
  56 .TP
  57 .I /etc/opt
  58 Host-specific configuration files for add-on applications installed
  59 in
  60 .IR /opt .
  61 .TP
  62 .I /etc/sgml
  63 This directory contains the configuration files for SGML (optional).
  64 .TP
  65 .I /etc/skel
  66 When a new user account is created, files from this directory are
  67 usually copied into the user's home directory.
  68 .TP
  69 .I /etc/X11
  70 Configuration files for the X11 window system (optional).
  71 .TP
  72 .I /etc/xml
  73 This directory contains the configuration files for XML (optional).
  74 .TP
  75 .I /home
  76 On machines with home directories for users, these are usually beneath
  77 this directory, directly or not.
  78 The structure of this directory
  79 depends on local administration decisions (optional).
  80 .TP
  81 .I /lib
  82 This directory should hold those shared libraries that are necessary
  83 to boot the system and to run the commands in the root filesystem.
  84 .TP
  85 .I /lib<qual>
  86 These directories are variants of
  87 .I /lib
  88 on system which support more than one binary format requiring separate
  89 libraries (optional).
  90 .TP
  91 .I /lib/modules
  92 Loadable kernel modules (optional).
  93 .TP
  94 .I /lost+found
  95 This directory contains items lost in the filesystem.
  96 These items are usually chunks of files mangled as a consequence of
  97 a faulty disk or a system crash.
  98 .TP
  99 .I /media
 100 This directory contains mount points for removable media such as CD
 101 and DVD disks or USB sticks.
 102 On systems where more than one device exists
 103 for mounting a certain type of media,
 104 mount directories can be created by appending a digit
 105 to the name of those available above starting with '0',
 106 but the unqualified name must also exist.
 107 .TP
 108 .I /media/floppy[1\-9]
 109 Floppy drive (optional).
 110 .TP
 111 .I /media/cdrom[1\-9]
 112 CD-ROM drive (optional).
 113 .TP
 114 .I /media/cdrecorder[1\-9]
 115 CD writer (optional).
 116 .TP
 117 .I /media/zip[1\-9]
 118 Zip drive (optional).
 119 .TP
 120 .I /media/usb[1\-9]
 121 USB drive (optional).
 122 .TP
 123 .I /mnt
 124 This directory is a mount point for a temporarily mounted filesystem.
 125 In some distributions,
 126 .I /mnt
 127 contains subdirectories intended to be used as mount points for several
 128 temporary filesystems.
 129 .TP
 130 .I /opt
 131 This directory should contain add-on packages that contain static files.
 132 .TP
 133 .I /proc
 134 This is a mount point for the
 135 .I proc
 136 filesystem, which provides information about running processes and
 137 the kernel.
 138 This pseudo-filesystem is described in more detail in
 139 .BR proc (5).
 140 .TP
 141 .I /root
 142 This directory is usually the home directory for the root user (optional).
 143 .TP
 144 .I /run
 145 This directory contains information which
 146 describes the system since it was booted.
 147 Once this purpose was served by
 148 .I /var/run
 149 and programs may continue to use it.
 150 .TP
 151 .I /sbin
 152 Like
 153 .IR /bin ,
 154 this directory holds commands needed to boot the system, but which are
 155 usually not executed by normal users.
 156 .TP
 157 .I /srv
 158 This directory contains site-specific data that is served by this system.
 159 .TP
 160 .I /sys
 161 This is a mount point for the sysfs filesystem, which provides information
 162 about the kernel like
 163 .IR /proc ,
 164 but better structured, following the formalism of kobject infrastructure.
 165 .TP
 166 .I /tmp
 167 This directory contains temporary files which may be deleted with no
 168 notice, such as by a regular job or at system boot up.
 169 .TP
 170 .I /usr
 171 This directory is usually mounted from a separate partition.
 172 It should hold only shareable, read-only data, so that it can be mounted
 173 by various machines running Linux.
 174 .TP
 175 .I /usr/X11R6
 176 The X\-Window system, version 11 release 6 (present in FHS 2.3, removed
 177 in FHS 3.0).
 178 .TP
 179 .I /usr/X11R6/bin
 180 Binaries which belong to the X\-Window system; often, there is a
 181 symbolic link from the more traditional
 182 .I /usr/bin/X11
 183 to here.
 184 .TP
 185 .I /usr/X11R6/lib
 186 Data files associated with the X\-Window system.
 187 .TP
 188 .I /usr/X11R6/lib/X11
 189 These contain miscellaneous files needed to run X;  Often, there is a
 190 symbolic link from
 191 .I /usr/lib/X11
 192 to this directory.
 193 .TP
 194 .I /usr/X11R6/include/X11
 195 Contains include files needed for compiling programs using the X11
 196 window system.
 197 Often, there is a symbolic link from
 198 .I /usr/include/X11
 199 to this directory.
 200 .TP
 201 .I /usr/bin
 202 This is the primary directory for executable programs.
 203 Most programs
 204 executed by normal users which are not needed for booting or for
 205 repairing the system and which are not installed locally should be
 206 placed in this directory.
 207 .TP
 208 .I /usr/bin/mh
 209 Commands for the MH mail handling system (optional).
 210 .TP
 211 .I /usr/bin/X11
 212 This is the traditional place to look for X11 executables; on Linux, it
 213 usually is a symbolic link to
 214 .IR /usr/X11R6/bin .
 215 .TP
 216 .I /usr/dict
 217 Replaced by
 218 .IR /usr/share/dict .
 219 .TP
 220 .I /usr/doc
 221 Replaced by
 222 .IR /usr/share/doc .
 223 .TP
 224 .I /usr/etc
 225 Site-wide configuration files to be shared between several machines
 226 may be stored in this directory.
 227 However, commands should always
 228 reference those files using the
 229 .I /etc
 230 directory.
 231 Links from files in
 232 .I /etc
 233 should point to the appropriate files in
 234 .IR /usr/etc .
 235 .TP
 236 .I /usr/games
 237 Binaries for games and educational programs (optional).
 238 .TP
 239 .I /usr/include
 240 Include files for the C compiler.
 241 .TP
 242 .I /usr/include/bsd
 243 BSD compatibility include files (optional).
 244 .TP
 245 .I /usr/include/X11
 246 Include files for the C compiler and the X\-Window system.
 247 This is
 248 usually a symbolic link to
 249 .IR /usr/X11R6/include/X11 .
 250 .TP
 251 .I /usr/include/asm
 252 Include files which declare some assembler functions.
 253 This used to be a
 254 symbolic link to
 255 .IR /usr/src/linux/include/asm .
 256 .TP
 257 .I /usr/include/linux
 258 This contains information which may change from system release to
 259 system release and used to be a symbolic link to
 260 .I /usr/src/linux/include/linux
 261 to get at operating-system-specific information.
 262 .IP
 263 (Note that one should have include files there that work correctly with
 264 the current libc and in user space.
 265 However, Linux kernel source is not
 266 designed to be used with user programs and does not know anything
 267 about the libc you are using.
 268 It is very likely that things will break
 269 if you let
 270 .I /usr/include/asm
 271 and
 272 .I /usr/include/linux
 273 point at a random kernel tree.
 274 Debian systems don't do this
 275 and use headers from a known good kernel
 276 version, provided in the libc*-dev package.)
 277 .TP
 278 .I /usr/include/g++
 279 Include files to use with the GNU C++ compiler.
 280 .TP
 281 .I /usr/lib
 282 Object libraries, including dynamic libraries, plus some executables
 283 which usually are not invoked directly.
 284 More complicated programs may
 285 have whole subdirectories there.
 286 .TP
 287 .I /usr/libexec
 288 Directory contains binaries for internal use only and they are not meant
 289 to be executed directly by users shell or scripts.
 290 .TP
 291 .I /usr/lib<qual>
 292 These directories are variants of
 293 .I /usr/lib
 294 on system which support more than one binary format requiring separate
 295 libraries, except that the symbolic link
 296 .I /usr/lib<qual>/X11
 297 is not required (optional).
 298 .TP
 299 .I /usr/lib/X11
 300 The usual place for data files associated with X programs, and
 301 configuration files for the X system itself.
 302 On Linux, it usually is
 303 a symbolic link to
 304 .IR /usr/X11R6/lib/X11 .
 305 .TP
 306 .I /usr/lib/gcc\-lib
 307 contains executables and include files for the GNU C compiler,
 308 .BR gcc (1).
 309 .TP
 310 .I /usr/lib/groff
 311 Files for the GNU groff document formatting system.
 312 .TP
 313 .I /usr/lib/uucp
 314 Files for
 315 .BR uucp (1).
 316 .TP
 317 .I /usr/local
 318 This is where programs which are local to the site typically go.
 319 .TP
 320 .I /usr/local/bin
 321 Binaries for programs local to the site.
 322 .TP
 323 .I /usr/local/doc
 324 Local documentation.
 325 .TP
 326 .I /usr/local/etc
 327 Configuration files associated with locally installed programs.
 328 .TP
 329 .I /usr/local/games
 330 Binaries for locally installed games.
 331 .TP
 332 .I /usr/local/lib
 333 Files associated with locally installed programs.
 334 .TP
 335 .I /usr/local/lib<qual>
 336 These directories are variants of
 337 .I /usr/local/lib
 338 on system which support more than one binary format requiring separate
 339 libraries (optional).
 340 .TP
 341 .I /usr/local/include
 342 Header files for the local C compiler.
 343 .TP
 344 .I /usr/local/info
 345 Info pages associated with locally installed programs.
 346 .TP
 347 .I /usr/local/man
 348 Man pages associated with locally installed programs.
 349 .TP
 350 .I /usr/local/sbin
 351 Locally installed programs for system administration.
 352 .TP
 353 .I /usr/local/share
 354 Local application data that can be shared among different architectures
 355 of the same OS.
 356 .TP
 357 .I /usr/local/src
 358 Source code for locally installed software.
 359 .TP
 360 .I /usr/man
 361 Replaced by
 362 .IR /usr/share/man .
 363 .TP
 364 .I /usr/sbin
 365 This directory contains program binaries for system administration
 366 which are not essential for the boot process, for mounting
 367 .IR /usr ,
 368 or for system repair.
 369 .TP
 370 .I /usr/share
 371 This directory contains subdirectories with specific application data, that
 372 can be shared among different architectures of the same OS.
 373 Often one finds stuff here that used to live in
 374 .I /usr/doc
 375 or
 376 .I /usr/lib
 377 or
 378 .IR /usr/man .
 379 .TP
 380 .I /usr/share/color
 381 Contains color management information, like International Color Consortium (ICC)
 382 Color profiles (optional).
 383 .TP
 384 .I /usr/share/dict
 385 Contains the word lists used by spell checkers (optional).
 386 .TP
 387 .I /usr/share/dict/words
 388 List of English words (optional).
 389 .TP
 390 .I /usr/share/doc
 391 Documentation about installed programs (optional).
 392 .TP
 393 .I /usr/share/games
 394 Static data files for games in
 395 .I /usr/games
 396 (optional).
 397 .TP
 398 .I /usr/share/info
 399 Info pages go here (optional).
 400 .TP
 401 .I /usr/share/locale
 402 Locale information goes here (optional).
 403 .TP
 404 .I /usr/share/man
 405 Manual pages go here in subdirectories according to the man page sections.
 406 .TP
 407 .I /usr/share/man/<locale>/man[1\-9]
 408 These directories contain manual pages for the
 409 specific locale in source code form.
 410 Systems which use a unique language and code set for all manual pages
 411 may omit the <locale> substring.
 412 .TP
 413 .I /usr/share/misc
 414 Miscellaneous data that can be shared among different architectures of the
 415 same OS.
 416 .TP
 417 .I /usr/share/nls
 418 The message catalogs for native language support go here (optional).
 419 .TP
 420 .I /usr/share/ppd
 421 Postscript Printer Definition (PPD) files (optional).
 422 .TP
 423 .I /usr/share/sgml
 424 Files for SGML (optional).
 425 .TP
 426 .I /usr/share/sgml/docbook
 427 DocBook DTD (optional).
 428 .TP
 429 .I /usr/share/sgml/tei
 430 TEI DTD (optional).
 431 .TP
 432 .I /usr/share/sgml/html
 433 HTML DTD (optional).
 434 .TP
 435 .I /usr/share/sgml/mathml
 436 MathML DTD (optional).
 437 .TP
 438 .I /usr/share/terminfo
 439 The database for terminfo (optional).
 440 .TP
 441 .I /usr/share/tmac
 442 Troff macros that are not distributed with groff (optional).
 443 .TP
 444 .I /usr/share/xml
 445 Files for XML (optional).
 446 .TP
 447 .I /usr/share/xml/docbook
 448 DocBook DTD (optional).
 449 .TP
 450 .I /usr/share/xml/xhtml
 451 XHTML DTD (optional).
 452 .TP
 453 .I /usr/share/xml/mathml
 454 MathML DTD (optional).
 455 .TP
 456 .I /usr/share/zoneinfo
 457 Files for timezone information (optional).
 458 .TP
 459 .I /usr/src
 460 Source files for different parts of the system, included with some packages
 461 for reference purposes.
 462 Don't work here with your own projects, as files
 463 below /usr should be read-only except when installing software (optional).
 464 .TP
 465 .I /usr/src/linux
 466 This was the traditional place for the kernel source.
 467 Some distributions put here the source for the default kernel they ship.
 468 You should probably use another directory when building your own kernel.
 469 .TP
 470 .I /usr/tmp
 471 Obsolete.
 472 This should be a link
 473 to
 474 .IR /var/tmp .
 475 This link is present only for compatibility reasons and shouldn't be used.
 476 .TP
 477 .I /var
 478 This directory contains files which may change in size, such as spool
 479 and log files.
 480 .TP
 481 .I /var/account
 482 Process accounting logs (optional).
 483 .TP
 484 .I /var/adm
 485 This directory is superseded by
 486 .I /var/log
 487 and should be a symbolic link to
 488 .IR /var/log .
 489 .TP
 490 .I /var/backups
 491 Reserved for historical reasons.
 492 .TP
 493 .I /var/cache
 494 Data cached for programs.
 495 .TP
 496 .I /var/cache/fonts
 497 Locally generated fonts (optional).
 498 .TP
 499 .I /var/cache/man
 500 Locally formatted man pages (optional).
 501 .TP
 502 .I /var/cache/www
 503 WWW proxy or cache data (optional).
 504 .TP
 505 .I /var/cache/<package>
 506 Package specific cache data (optional).
 507 .TP
 508 .IR /var/catman/cat[1\-9] " or " /var/cache/man/cat[1\-9]
 509 These directories contain preformatted manual pages according to their
 510 man page section.
 511 (The use of preformatted manual pages is deprecated.)
 512 .TP
 513 .I /var/crash
 514 System crash dumps (optional).
 515 .TP
 516 .I /var/cron
 517 Reserved for historical reasons.
 518 .TP
 519 .I /var/games
 520 Variable game data (optional).
 521 .TP
 522 .I /var/lib
 523 Variable state information for programs.
 524 .TP
 525 .I /var/lib/color
 526 Variable files containing color management information (optional).
 527 .TP
 528 .I /var/lib/hwclock
 529 State directory for hwclock (optional).
 530 .TP
 531 .I /var/lib/misc
 532 Miscellaneous state data.
 533 .TP
 534 .I /var/lib/xdm
 535 X display manager variable data (optional).
 536 .TP
 537 .I /var/lib/<editor>
 538 Editor backup files and state (optional).
 539 .TP
 540 .I /var/lib/<name>
 541 These directories must be used for all distribution packaging support.
 542 .TP
 543 .I /var/lib/<package>
 544 State data for packages and subsystems (optional).
 545 .TP
 546 .I /var/lib/<pkgtool>
 547 Packaging support files (optional).
 548 .TP
 549 .I /var/local
 550 Variable data for
 551 .IR /usr/local .
 552 .TP
 553 .I /var/lock
 554 Lock files are placed in this directory.
 555 The naming convention for
 556 device lock files is
 557 .I LCK..<device>
 558 where
 559 .I <device>
 560 is the device's name in the filesystem.
 561 The format used is that of HDU UUCP lock files, that is, lock files
 562 contain a PID as a 10-byte ASCII decimal number, followed by a newline
 563 character.
 564 .TP
 565 .I /var/log
 566 Miscellaneous log files.
 567 .TP
 568 .I /var/opt
 569 Variable data for
 570 .IR /opt .
 571 .TP
 572 .I /var/mail
 573 Users' mailboxes.
 574 Replaces
 575 .IR /var/spool/mail .
 576 .TP
 577 .I /var/msgs
 578 Reserved for historical reasons.
 579 .TP
 580 .I /var/preserve
 581 Reserved for historical reasons.
 582 .TP
 583 .I /var/run
 584 Run-time variable files, like files holding process identifiers (PIDs)
 585 and logged user information
 586 .IR (utmp) .
 587 Files in this directory are usually cleared when the system boots.
 588 .TP
 589 .I /var/spool
 590 Spooled (or queued) files for various programs.
 591 .TP
 592 .I /var/spool/at
 593 Spooled jobs for
 594 .BR at (1).
 595 .TP
 596 .I /var/spool/cron
 597 Spooled jobs for
 598 .BR cron (8).
 599 .TP
 600 .I /var/spool/lpd
 601 Spooled files for printing (optional).
 602 .TP
 603 .I /var/spool/lpd/printer
 604 Spools for a specific printer (optional).
 605 .TP
 606 .I /var/spool/mail
 607 Replaced by
 608 .IR /var/mail .
 609 .TP
 610 .I /var/spool/mqueue
 611 Queued outgoing mail (optional).
 612 .TP
 613 .I /var/spool/news
 614 Spool directory for news (optional).
 615 .TP
 616 .I /var/spool/rwho
 617 Spooled files for
 618 .BR rwhod (8)
 619 (optional).
 620 .TP
 621 .I /var/spool/smail
 622 Spooled files for the
 623 .BR smail (1)
 624 mail delivery program.
 625 .TP
 626 .I /var/spool/uucp
 627 Spooled files for
 628 .BR uucp (1)
 629 (optional).
 630 .TP
 631 .I /var/tmp
 632 Like
 633 .IR /tmp ,
 634 this directory holds temporary files stored for an unspecified duration.
 635 .TP
 636 .I /var/yp
 637 Database files for NIS,
 638 formerly known as the Sun Yellow Pages (YP).
 639 .SH STANDARDS
 640 The Filesystem Hierarchy Standard (FHS), Version 3.0, published March 19, 2015
 641 .UR https://refspecs.linuxfoundation.org/fhs.shtml
 642 .UE .
 643 .SH BUGS
 644 This list is not exhaustive;
 645 different distributions and systems may be configured differently.
 646 .SH SEE ALSO
 647 .BR find (1),
 648 .BR ln (1),
 649 .BR proc (5),
 650 .BR file\-hierarchy (7),
 651 .BR mount (8)
 652 .PP
 653 The Filesystem Hierarchy Standard