HIER

Section: Linux Programmer's Manual (7)
Updated: April 24, 1993
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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 executed often, are needed to bring the system up or repair it.
/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 programs and other files necessary to system administration; normal users don't need any of this. Usually, this directory is not in their $PATH.
/etc/skel: When a new user account is created, files from this directory are usually copied into the user's home directory.
/etc/lilo: The Linux Loader for booting the system goes here.
/install: This is used by some installations scripts to keep track of which packages have been installed.
/lib: Frequently-used object code libraries, including dynamic libraries, which are linked at the time an executable starts up, plus some executables which usually are not called directly.
/proc: This is the directory where information about running processes can be obtained.
/proc/[0-9]+: This directory contains information about the process associated with its number; it has such files as the command line, the environment, the memory contents, or statistics about the process.
/proc/[0-9]+/fd: A directory containing the file descriptors associated with the process.
/proc/[0-9]+/lib: A directory containing the dynamic libraries associated with a process.
/proc/self: This is a link to the directory associated with the calling process.
/tmp: This directory contains temporary files which may be deleted with no notice, such as by a regular job or at system boot up.
/user: This often is an empty directory, which can be used as a mount point for floppy disks.
/usr: Less-frequently used commands and other things; this is often a mount point for a separate partition or volume.
/usr/TeX: The TeX typesetting system.
/usr/TeX/bin: Binary commands for the TeX system. /usr/TeX/lib This contains data files connected with TeX, and may contain further subdirectories.
/usr/TeX/man: Manual pages with the TeX system.
/usr/TeX/src: Sources associates with TeX.
/usr/X386: The X-Windows system.
/usr/X386/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/X386/lib: Data files associated with the X-Windows system.
/usr/X386/lib/X11: These contain miscellaneous files needed to run X; among them configuration files. Often, there is a symbolic link from /usr/lib/X11 to this directory.
/usr/adm: This often contains various log files.
/usr/bin: This contains binaries which are not needed so often, or are not needed for bringing the system up or repairing it. The decision whether to put something in /bin or /usr/bin should be guided by the simple consideration: "If I put it in /usr/bin and /usr is not available on boot, do I still get the system up?"
/usr/bin/X11: is the traditional place to look for X11 executables; on Linux, it usually is a symbolic link to /usr/X386/bin.
/usr/g++-include: Include files to use with the GNU C++ compiler.
/usr/homes: This contains the home directories for normal users.
/usr/include: Include files for the C compiler.
/usr/include/X11: Include files for the C compiler and the X-Windows system.
/usr/include/asm: Include files which declare some assembler functions. This should 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 should be a symbolic link to /usr/src/linux/include/linux to get at operating system specific information.
/usr/lib: Less - frequently used 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/X386/lib/X11.
/usr/lib/X11/app-defaults: X applications store their default resource (in other words, application defaults) here. If you want to change the way a certain program looks, this is the place to look.
/usr/lib/X11/config: This directory is used for the imake(1) utility which incorporates information about the system into Makefiles.
/usr/lib/X11/twm: Files for the twm(1) window manager.
/usr/lib/X11/xinit: Files for starting up the X Windows system.
/usr/lib/gcc-lib: contains configuration files for the system's C compiler, gcc(1).
/usr/lib/groff: Files for the 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 in. Some program packages, such as EMACS, may have their own subdirectories there.
/usr/local/bin: Binaries for programs local to the site go there.
/usr/local/lib: Files associated with locally installed programs go there.
/usr/local/man: Manpages associated with locally installed programs go there.
/usr/man: Manpages go in there, into their subdirectories.
/usr/man/cat[1-9]: These directories contain preformatted manual pages according to their manpage section.
/usr/man/man[1-9]: These directories contain manual pages which are in source code form.
/usr/openwin: Files associated with the Open Windows Window manager for X go there.
/usr/preserve: This is where vi(1) saves edit sessions so they can be restored later.
/usr/spool: Spooled (or queued) files for various programs.
/usr/spool/atjobs: Spooled jobs for at(1).
/usr/spool/cron: Spooled jobs for cron(1).
/usr/spool/lp1: Spooled files for a printer.
/usr/spool/mail: User's mailboxes.
/usr/spool/smail: Spooled files for the smail(1) mail delivery program.
/usr/spool/uucp: Spooled files for uucp(1).
/usr/src: Source files for different parts of the system.
/usr/src/libc-linux: Sources for the C library.
/usr/src/linux: This contains the sources for the operating system itself.
/usr/tmp: An alternative place to store temporary files; often used if the files will be huge.
/var: On some systems with more of a BSD flavour to them, this directory contains all the files which may change in size, such as spool and log files, and /usr only contains static files. Often, /var is just a symbolic link to /usr.

CONFORMS TO

The layout of this file system generally follows System V conventions.

BUGS

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