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
	      located 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 sub-
	      directories below /etc.  Site-wide configuration	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 decisions (optional).

       /lib   This  directory should hold those shared libraries that are nec-
	      essary to boot the system 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 direc-
	      tories 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 distributions, /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  running  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).

       /sbin  Like /bin, this directory holds commands needed to boot the sys-
	      tem, but which are usually 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 infrastructure.

       /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  sharable,  read-only data, so that it can be
	      mounted by various machines running Linux.

       /usr/X11R6
	      The X-Window system, version 11 release 6 (optional).

       /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.   Often,  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 normal users which are not needed for boot-
	      ing 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 symbolic 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 cor-
	      rectly 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  sys-
	      tems don't do this and use headers from a known good kernel ver-
	      sion, 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  exe-
	      cutables	which  usually are not invoked directly.  More compli-
	      cated programs may have whole subdirectories there.

       /usr/lib<qual>
	      These directories are variants of /usr/lib on system which  sup-
	      port  more  than one binary 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  usu-
	      ally 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 archi-
	      tectures 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 administra-
	      tion which are not essential 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/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 architec-
	      tures of the same OS.

       /usr/share/nls
	      The  message  catalogs  for  native  language  support  go  here
	      (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 reference 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 dis-
	      tributions 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 compatibility 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 sym-
	      bolic 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 section.	 (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/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 direc-
	      tory 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, Version 2.3 <http://www.pathname.com
       /fhs/>.

BUGS
       This list is not exhaustive; different systems may be  configured  dif-
       ferently.

SEE ALSO
       find(1), ln(1), proc(5), mount(8)

       The Filesystem Hierarchy Standard

COLOPHON
       This  page  is  part of release 4.10 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				  2015-03-29			       HIER(7)