The following is being submitted by Alan Clegg [abc@concert.net] on behalf of the linux-standards group as the recommended standard for directory file structure under Linux. Complete implementation of this file structure is completely voluntary, and will not be enforced, but will be recommended. This specification is released as guidelines for people porting and writing software for the Linux Operating System to allow easy software installation, upgrade, and tailoring on already installed systems. Root Directory: Files: {none defined by spec} Directories: bin dev etc home lib mnt usr Rationale: The root directory should not be cluttered with files or directories, and should contain no user programs. /bin Directory: Files: sh init mount umount dd cat ls fsck mkfs {and as needed} Directories: {none defined by spec} Rationale: The /bin directory should contain programs that are vital to the restoration of other file systems in the case of a corrupting crash. No executable in /bin should require any other file system to be mounted to execute correctly. /dev Directory: Files: {device files} Directories: {none define by spec} Rationale: Standard UNIX device files. This directory should contain device entries for all devices that are supported in the standard kernel, even if the hardware device does not exist on the system. Note that the distribution will have all device files, but they may be removed by the user upon system installation. /etc Directory: Files: mtab passwd rc ttytab {and as needed} Directories: {none defined by spec} Rationale: Standard location of files required during system boot. Files in this directory are usually system specific. Most will require human intervention during system upgrade. /home Directory: Files: NONE Directories: {one per user excepting root} Rationale: Standard location of users home directories. Will most likely be a mounted file system once the system is up. root's home directory should be /. /lib Directory: Files: {libraries required for system initialization} Directories: {none defined by spec} Rationale: To keep the size of the root partition small (if separate from /usr), the files in this directory should only be ones required by files in the root partition. /mnt Directory: Files: NONE Directories: NONE Rationale: Standard mount point for external (transient) file systems. Must be available for sub-system installation. Should remain as an empty directory. /tmp Directory: Files: NONE Directories: NONE Rationale: Temporary file space available for general program use. May become a mounted partition upon system boot. /usr Directory: Files: {none defined by spec} Directories: adm bin spool local lib etc man include src tmp Rationale: /usr is the mount point for the second major (after root) hierarchy of file structure and is discussed in the next section. /usr/adm Directory: Files: {none defined in spec} Directories: {none defined in spec} Rationale: Location of log files and accounting information. /usr/bin Directory: Files: {all executable files from standard distribution not contined in /bin} Directories: {none defined in spec} Rationale: contains 'drop-in' executables that are considered to be standard to the UNIX system. These files should NOT be Linux specific, but should have the same function as their UNIX equivalents. /usr/etc Directory: Files: {none defined in spec} Directories: {none defined in spec} Rationale: contains configuration files for any files in /usr/bin. helps to keep /etc clean and small. /usr/spool Directory: Files: {none defined in spec} Directories: uucp mail Rationale: containes spool files for mail, printing, uucp transfer, etc. May be a mount point for another volume. /usr/local Directory: Files: NONE Directories: bin lib etc man src Rationale: contains files local to the specific system. will not be modified by upgrade process. /usr/lib Directory: Files: libc.a crt0.s {and as needed} Directories: {none defined in spec} Rationale: location for library files required for multi-user system operation. This is the directory where program libraries should reside. /usr/man Directory: Files: NONE Directories: man1 man2 man3 man4 man5 man6 man7 man8 cat1 cat2 cat3 cat4 cat5 cat6 cat7 cat8 Rationale: Contains manual pages for programs that are standard with Linux. /usr/include Directory: Files: {programmers include files} Directories: {as needed} Rationale: Standard place for system include files. /usr/src Directory: Files: NONE Directories: bin lib linux usr.bin usr.lib Rationale: Contains source code for all applications in the release. /usr/src/linux contains directories required for kernel builds. /usr/tmp Directory: Files: NONE Directories: NONE Rationale: Used as additional scratch space for programs. If /tmp is a mounted file system, /usr/tmp may be a symbolic link to /tmp.