HIER(7)

NAME
hier - Description of the file system 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 only holds the files which are needed during the boot process. The map installer and configuration files should go to /sbin and /etc.

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

/dos
    If both MS-DOS and Linux are run on one computer, this is a typical place to mount a DOS file system.

/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 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/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.

/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 admininstration decisions.

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

/mnt
    is a mount point for temporarily mounted filesystems

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

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

/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 seperate 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.

/usr/X11R6/bin
    Binaries which belong to the X-Windows 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-Windows 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/inlcude/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 booting or for repairing the system and which are not installed locally should be placed in this directory.

/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
    This directory holds files containing word lists for spell checkers.

/usr/doc
    You may find documentation about the installed software packages in this directory.

/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/include
    Include files for the C compiler.

/usr/include/X11
    Include files for the C compiler and the X-Windows 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/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/lib/zoneinfo
    Files for timezone information.

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

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

/usr/local/doc
    Local documentation

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

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

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

/usr/local/man
    Manpages associated with locally installed programs go there.

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

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

/usr/man
    Manpages traditionally go in there, into their subdirectories.

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

/usr/sbin
    This directory contains program binaries for system admininstration 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/doc

/usr/share/man
    Manpages go in there, into their subdirectories.

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

/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.

/usr/src/linux
    This has always been the traditional place where kernel sources were unpacked. This was important on systems that /usr/include/linux was a symlink here. You should probably use another directory for building the kernel now.

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

/var/backups
    This directory is used to save backup copies of important system files.

/var/cache/man/cat[1-9]
    These directories contain preformatted manual pages according to their manpage section.

/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, i.e. lock files contain a PID as a 10-byte ASCII decimal number, followed by a newline character.

/var/log
    Miscelanous log files.

/var/preserve
    This is where vi(1) saves edit sessions so they can be restored later.

/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(1).

/var/spool/lpd
    Spooled files for printing.

/var/spool/mail
    Users' mailboxes.

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

/var/spool/news
    Spool directory for the news subsystem.

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

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

CONFORMS TO
The Linux filesystem standard, Release 1.2

BUGS
This list is not exhaustive; different systems may be configured differently.

SEE ALSO
find(1), ln(1), mount(1), proc(5), The Linux Filesystem Standard