phpman > man > hier(7)

HIER(7)                               Linux Programmer's Manual                              HIER(7)



NAME
       hier - description of the filesystem hierarchy

DESCRIPTION
       A typical Linux system has, among others, the following directories:

       /      This is the root directory.  This is where the whole tree starts.

       /bin   This  directory  contains executable programs which are needed in single user mode and
              to bring the system up or repair it.

       /boot  Contains static files for the boot loader.  This directory holds only the files  which
              are  needed during the boot process.  The map installer and configuration files should
              go to /sbin and /etc.  The operating system kernel (initrd for example)  must  be  lo‐
              cated in either / or /boot.

       /dev   Special or device files, which refer to physical devices.  See mknod(1).

       /etc   Contains  configuration  files  which  are local to the machine.  Some larger software
              packages, like X11, can have their own subdirectories below /etc.  Site-wide  configu‐
              ration  files may be placed here or in /usr/etc.  Nevertheless, programs should always
              look for these files in /etc and you may have links for these files to /usr/etc.

       /etc/opt
              Host-specific configuration files for add-on applications installed in /opt.

       /etc/sgml
              This directory contains the configuration files for SGML (optional).

       /etc/skel
              When a new user account is created, files from this directory are usually copied  into
              the user's home directory.

       /etc/X11
              Configuration files for the X11 window system (optional).

       /etc/xml
              This directory contains the configuration files for XML (optional).

       /home  On machines with home directories for users, these are usually beneath this directory,
              directly or not.  The structure of this directory depends on local administration  de‐
              cisions (optional).

       /lib   This  directory should hold those shared libraries that are necessary to boot the sys‐
              tem and to run the commands in the root filesystem.

       /lib<qual>
              These directories are variants of /lib on system which support more  than  one  binary
              format requiring separate libraries (optional).

       /lib/modules
              Loadable kernel modules (optional).

       /lost+found
              This  directory contains items lost in the filesystem.  These items are usually chunks
              of files mangled as a consequence of a faulty disk or a system crash.

       /media This directory contains mount points for removable media such as CD and DVD  disks  or
              USB  sticks.  On systems where more than one device exists for mounting a certain type
              of media, mount directories can be created by appending a digit to the name  of  those
              available above starting with '0', but the unqualified name must also exist.

       /media/floppy[1-9]
              Floppy drive (optional).

       /media/cdrom[1-9]
              CD-ROM drive (optional).

       /media/cdrecorder[1-9]
              CD writer (optional).

       /media/zip[1-9]
              Zip drive (optional).

       /media/usb[1-9]
              USB drive (optional).

       /mnt   This directory is a mount point for a temporarily mounted filesystem.  In some distri‐
              butions, /mnt contains subdirectories intended to be used as mount points for  several
              temporary filesystems.

       /opt   This directory should contain add-on packages that contain static files.

       /proc  This  is  a mount point for the proc filesystem, which provides information about run‐
              ning processes and the kernel.  This pseudo-filesystem is described in more detail  in
              proc(5).

       /root  This directory is usually the home directory for the root user (optional).

       /run   This  directory  contains  information which describes the system since it was booted.
              Once this purpose was served by /var/run and programs may continue to use it.

       /sbin  Like /bin, this directory holds commands needed to boot the system, but which are usu‐
              ally not executed by normal users.

       /srv   This directory contains site-specific data that is served by this system.

       /sys   This  is  a mount point for the sysfs filesystem, which provides information about the
              kernel like /proc, but better structured, following the formalism  of  kobject  infra‐
              structure.

       /tmp   This  directory  contains temporary files which may be deleted with no notice, such as
              by a regular job or at system boot up.

       /usr   This directory is usually mounted from a separate  partition.   It  should  hold  only
              shareable,  read-only  data,  so  that  it  can be mounted by various machines running
              Linux.

       /usr/X11R6
              The X-Window system, version 11 release 6 (present in FHS 2.3, removed in FHS 3.0).

       /usr/X11R6/bin
              Binaries which belong to the X-Window system; often, there is a symbolic link from the
              more traditional /usr/bin/X11 to here.

       /usr/X11R6/lib
              Data files associated with the X-Window system.

       /usr/X11R6/lib/X11
              These  contain  miscellaneous  files needed to run X;  Often, there is a symbolic link
              from /usr/lib/X11 to this directory.

       /usr/X11R6/include/X11
              Contains include files needed for compiling programs using the X11 window system.  Of‐
              ten, there is a symbolic link from /usr/include/X11 to this directory.

       /usr/bin
              This is the primary directory for executable programs.  Most programs executed by nor‐
              mal users which are not needed for booting or for repairing the system and  which  are
              not installed locally should be placed in this directory.

       /usr/bin/mh
              Commands for the MH mail handling system (optional).

       /usr/bin/X11
              is  the  traditional place to look for X11 executables; on Linux, it usually is a sym‐
              bolic link to /usr/X11R6/bin.

       /usr/dict
              Replaced by /usr/share/dict.

       /usr/doc
              Replaced by /usr/share/doc.

       /usr/etc
              Site-wide configuration files to be shared between several machines may be  stored  in
              this  directory.  However, commands should always reference those files using the /etc
              directory.  Links from files  in  /etc  should  point  to  the  appropriate  files  in
              /usr/etc.

       /usr/games
              Binaries for games and educational programs (optional).

       /usr/include
              Include files for the C compiler.

       /usr/include/bsd
              BSD compatibility include files (optional).

       /usr/include/X11
              Include  files for the C compiler and the X-Window system.  This is usually a symbolic
              link to /usr/X11R6/include/X11.

       /usr/include/asm
              Include files which declare some assembler functions.  This used to be a symbolic link
              to /usr/src/linux/include/asm.

       /usr/include/linux
              This  contains  information which may change from system release to system release and
              used to be a symbolic link to /usr/src/linux/include/linux to get at operating-system-
              specific information.

              (Note  that  one  should have include files there that work correctly with the current
              libc and in user space.  However, Linux kernel source is not designed to be used  with
              user  programs  and  does  not know anything about the libc you are using.  It is very
              likely that things will break if you let /usr/include/asm and /usr/include/linux point
              at  a  random  kernel tree.  Debian systems don't do this and use headers from a known
              good kernel version, provided in the libc*-dev package.)

       /usr/include/g++
              Include files to use with the GNU C++ compiler.

       /usr/lib
              Object libraries, including dynamic libraries, plus some executables which usually are
              not invoked directly.  More complicated programs may have whole subdirectories there.

       /usr/libexec
              Directory  contains  binaries  for internal use only and they are not meant to be exe‐
              cuted directly by users shell or scripts.

       /usr/lib<qual>
              These directories are variants of /usr/lib on system which support more than  one  bi‐
              nary   format   requiring   separate   libraries,   except   that  the  symbolic  link
              /usr/lib<qual>/X11 is not required (optional).

       /usr/lib/X11
              The usual place for data files associated with X programs, and configuration files for
              the X system itself.  On Linux, it usually is a symbolic link to /usr/X11R6/lib/X11.

       /usr/lib/gcc-lib
              contains executables and include files for the GNU C compiler, gcc(1).

       /usr/lib/groff
              Files for the GNU groff document formatting system.

       /usr/lib/uucp
              Files for uucp(1).

       /usr/local
              This is where programs which are local to the site typically go.

       /usr/local/bin
              Binaries for programs local to the site.

       /usr/local/doc
              Local documentation.

       /usr/local/etc
              Configuration files associated with locally installed programs.

       /usr/local/games
              Binaries for locally installed games.

       /usr/local/lib
              Files associated with locally installed programs.

       /usr/local/lib<qual>
              These directories are variants of /usr/local/lib on system which support more than one
              binary format requiring separate libraries (optional).

       /usr/local/include
              Header files for the local C compiler.

       /usr/local/info
              Info pages associated with locally installed programs.

       /usr/local/man
              Man pages associated with locally installed programs.

       /usr/local/sbin
              Locally installed programs for system administration.

       /usr/local/share
              Local application data that can be shared among different architectures  of  the  same
              OS.

       /usr/local/src
              Source code for locally installed software.

       /usr/man
              Replaced by /usr/share/man.

       /usr/sbin
              This  directory  contains program binaries for system administration which are not es‐
              sential for the boot process, for mounting /usr, or for system repair.

       /usr/share
              This directory contains subdirectories with specific application  data,  that  can  be
              shared  among different architectures of the same OS.  Often one finds stuff here that
              used to live in /usr/doc or /usr/lib or /usr/man.

       /usr/share/color
              Contains color management information, like International Color Consortium (ICC) Color
              profiles (optional).

       /usr/share/dict
              Contains the word lists used by spell checkers (optional).

       /usr/share/dict/words
              List of English words (optional).

       /usr/share/doc
              Documentation about installed programs (optional).

       /usr/share/games
              Static data files for games in /usr/games (optional).

       /usr/share/info
              Info pages go here (optional).

       /usr/share/locale
              Locale information goes here (optional).

       /usr/share/man
              Manual pages go here in subdirectories according to the man page sections.

       /usr/share/man/<locale>/man[1-9]
              These  directories  contain  manual pages for the specific locale in source code form.
              Systems which use a unique language and code set for all manual  pages  may  omit  the
              <locale> substring.

       /usr/share/misc
              Miscellaneous data that can be shared among different architectures of the same OS.

       /usr/share/nls
              The message catalogs for native language support go here (optional).

       /usr/share/ppd
              Postscript Printer Definition (PPD) files (optional).

       /usr/share/sgml
              Files for SGML (optional).

       /usr/share/sgml/docbook
              DocBook DTD (optional).

       /usr/share/sgml/tei
              TEI DTD (optional).

       /usr/share/sgml/html
              HTML DTD (optional).

       /usr/share/sgml/mathtml
              MathML DTD (optional).

       /usr/share/terminfo
              The database for terminfo (optional).

       /usr/share/tmac
              Troff macros that are not distributed with groff (optional).

       /usr/share/xml
              Files for XML (optional).

       /usr/share/xml/docbook
              DocBook DTD (optional).

       /usr/share/xml/xhtml
              XHTML DTD (optional).

       /usr/share/xml/mathml
              MathML DTD (optional).

       /usr/share/zoneinfo
              Files for timezone information (optional).

       /usr/src
              Source files for different parts of the system, included with some packages for refer‐
              ence purposes.  Don't work here with your own projects, as files below /usr should  be
              read-only except when installing software (optional).

       /usr/src/linux
              This was the traditional place for the kernel source.  Some distributions put here the
              source for the default kernel they ship.  You should probably  use  another  directory
              when building your own kernel.

       /usr/tmp
              Obsolete.   This should be a link to /var/tmp.  This link is present only for compati‐
              bility reasons and shouldn't be used.

       /var   This directory contains files which may change in size, such as spool and log files.

       /var/account
              Process accounting logs (optional).

       /var/adm
              This directory is superseded by /var/log and should be a symbolic link to /var/log.

       /var/backups
              Reserved for historical reasons.

       /var/cache
              Data cached for programs.

       /var/cache/fonts
              Locally generated fonts (optional).

       /var/cache/man
              Locally formatted man pages (optional).

       /var/cache/www
              WWW proxy or cache data (optional).

       /var/cache/<package>
              Package specific cache data (optional).

       /var/catman/cat[1-9] or /var/cache/man/cat[1-9]
              These directories contain preformatted manual pages according to their man  page  sec‐
              tion.  (The use of preformatted manual pages is deprecated.)

       /var/crash
              System crash dumps (optional).

       /var/cron
              Reserved for historical reasons.

       /var/games
              Variable game data (optional).

       /var/lib
              Variable state information for programs.

       /var/lib/color
              Variable files containing color management information (optional).

       /var/lib/hwclock
              State directory for hwclock (optional).

       /var/lib/misc
              Miscellaneous state data.

       /var/lib/xdm
              X display manager variable data (optional).

       /var/lib/<editor>
              Editor backup files and state (optional).

       /var/lib/<name>
              These directories must be used for all distribution packaging support.

       /var/lib/<package>
              State data for packages and subsystems (optional).

       /var/lib/<pkgtool>
              Packaging support files (optional).

       /var/local
              Variable data for /usr/local.

       /var/lock
              Lock  files are placed in this directory.  The naming convention for device lock files
              is LCK..<device> where <device> is the device's name in the  filesystem.   The  format
              used  is  that  of HDU UUCP lock files, that is, lock files contain a PID as a 10-byte
              ASCII decimal number, followed by a newline character.

       /var/log
              Miscellaneous log files.

       /var/opt
              Variable data for /opt.

       /var/mail
              Users' mailboxes.  Replaces /var/spool/mail.

       /var/msgs
              Reserved for historical reasons.

       /var/preserve
              Reserved for historical reasons.

       /var/run
              Run-time variable files, like files holding process identifiers (PIDs) and logged user
              information  (utmp).   Files  in  this  directory  are usually cleared when the system
              boots.

       /var/spool
              Spooled (or queued) files for various programs.

       /var/spool/at
              Spooled jobs for at(1).

       /var/spool/cron
              Spooled jobs for cron(8).

       /var/spool/lpd
              Spooled files for printing (optional).

       /var/spool/lpd/printer
              Spools for a specific printer (optional).

       /var/spool/mail
              Replaced by /var/mail.

       /var/spool/mqueue
              Queued outgoing mail (optional).

       /var/spool/news
              Spool directory for news (optional).

       /var/spool/rwho
              Spooled files for rwhod(8) (optional).

       /var/spool/smail
              Spooled files for the smail(1) mail delivery program.

       /var/spool/uucp
              Spooled files for uucp(1) (optional).

       /var/tmp
              Like /tmp, this directory holds temporary files stored for an unspecified duration.

       /var/yp
              Database files for NIS, formerly known as the Sun Yellow Pages (YP).

CONFORMING TO
       The  Filesystem  Hierarchy  Standard  (FHS),  Version   3.0,   published   March   19,   2015
       ⟨https://refspecs.linuxfoundation.org/fhs.shtml⟩.

BUGS
       This  list  is  not exhaustive; different distributions and systems may be configured differ‐
       ently.

SEE ALSO
       find(1), ln(1), proc(5), file-hierarchy(7), mount(8)

       The Filesystem Hierarchy Standard

COLOPHON
       This page is part of release 5.10 of the Linux  man-pages  project.   A  description  of  the
       project,  information about reporting bugs, and the latest version of this page, can be found
       at https://www.kernel.org/doc/man-pages/.



Linux                                        2020-06-09                                      HIER(7)