man7/hier.7

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