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28 .\" @(#)hier.7 8.1 (Berkeley) 6/5/93
36 .Nd layout of file systems
38 A sketch of the file system hierarchy.
39 .Bl -tag -width "/libexec/"
41 root directory of the file system
43 user utilities fundamental to both single-user and multi-user environments
45 programs and configuration files used during operating system bootstrap
47 .Bl -tag -width "defaults/" -compact
49 default bootstrapping configuration files; see
52 Compiled flattened device tree (FDT) files; see
57 loadable kernel modules containing binary firmware for hardware that needs
58 firmware downloaded to it to function
60 pure kernel executable (the operating system loaded into memory
61 at boot time) and kernel modules
63 third-party loadable kernel modules;
67 Compiled flattened device tree (FDT) overlays; see
76 default mount point for CD-ROM drives
84 device special files managed by
87 .Bl -tag -width "defaults/" -compact
89 file descriptor files;
94 system configuration files and scripts
96 .Bl -tag -width "defaults/" -compact
98 default system configuration files;
102 bluetooth configuration files
104 local timezone information;
108 Sendmail control files
110 mtree configuration files;
114 configuration files for the Pluggable Authentication Modules (PAM)
117 scripts that are run daily, weekly, and monthly, via
122 system and daemon startup/control scripts;
126 OpenBSM audit configuration files;
130 ppp configuration files;
134 OpenSSH configuration files;
138 OpenSSL configuration files
141 critical system libraries needed for binaries in
146 .Bl -tag -width "defaults/" -compact
148 class-specific libraries for the
153 critical system utilities needed for binaries in
158 contains subdirectories to be used as mount points
159 for removable media such as CDs, USB drives, and
162 empty directory commonly used by
163 system administrators as a temporary mount point
165 automounted NFS shares;
173 statically linked programs for emergency recovery;
177 root's HOME directory
179 system programs and administration utilities
180 fundamental to both single-user and multi-user environments
182 temporary files that are not guaranteed to persist across system reboots
184 contains the majority of user utilities and applications
186 .Bl -tag -width "defaults/" -compact
188 common utilities, programming tools, and applications
190 files needed to support binary compatibility with other operating systems,
193 standard C include files
195 .Bl -tag -width "kerberos5/" -compact
197 C include files for Internet service protocols
199 C include files for the SNMP daemon
203 C include files for the Common Access Methods Layer
204 .Bl -tag -width "kerberos5/" -compact
206 SCSI device on top of CAM
209 C include files for programming various
212 .Bl -tag -width "kerberos5/" -compact
214 various header files describing driver- and bus-independent
217 Open Firmware support
233 .Bl -tag -width "kerberos5/" -compact
235 per-process file descriptors file system
239 C include files for NFS (Network File System) version 2, 3 and 4
253 .Bl -tag -width "kerberos5/" -compact
268 C include files for libmilter,
273 machine-specific C include files
275 miscellaneous network C include files
276 .Bl -tag -width Fl -compact
278 C include files for alternate queueing
281 C include files for 802.11 wireless networking;
285 C include files for Internet standard protocols;
289 C include files for Internet protocol version 6;
293 kernel key-management service;
299 C include files for NFS (Network File System) version 2 and 3 (legacy)
301 OpenSSL (Cryptography/SSL toolkit) headers
303 C include files for Berkeley service protocols
305 remote procedure calls;
309 definition of RPC service structures; see
315 system C include files (kernel data structures)
320 .\" .Bl -tag -width "kerberos5/" -compact
327 C include files for UFS (The U-word File System)
328 .Bl -tag -width "kerberos5/" -compact
345 .Bl -tag -width Fl -compact
347 a.out archive libraries
349 shared libraries for compatibility
350 .Bl -tag -width Fl -compact
352 a.out backward compatibility libraries
355 standalone debug data for the kernel and base system libraries and binaries
357 DTrace library scripts
359 OpenSSL (Cryptography/SSL toolkit) dynamically loadable engines
363 miscellaneous utility data files
365 .Bl -tag -width Fl -compact
376 system daemons & system utilities (executed by other programs)
378 .Bl -tag -width Fl -compact
380 utilities to manipulate a.out executables
382 utilities to manipulate ELF executables
384 utilities and filters for LP print system;
401 local executables, libraries, etc.
402 Also used as the default destination for the
407 the general layout sketched out by
418 .Pa local/share/ Ns Pc ,
421 .Pa share/doc/<port>/ Ns Pc ,
427 architecture-specific target tree produced by building the
436 system daemons & system utilities (executed by users)
438 architecture-independent files
440 .Bl -tag -width Fl -compact
442 a variety of pre-fab calendar files;
449 .Bl -tag -width Fl -compact
452 terms, proper names, and jargon
454 words from Webster's 2nd International
457 miscellaneous documentation;
458 source for most of the printed
464 .Bl -tag -width Fl -compact
466 Frequently Asked Questions
468 implementation notes for IPv6
470 Spanish translations of documents in /usr/share/doc
475 Japanese translations of documents in /usr/share/doc
477 License files for vendor supplied firmware files
479 HTML documents pertaining to ncurses;
483 HTML documents pertaining to the Network Time Protocol
485 Russian translations of documents in /usr/share/doc
490 Chinese translations of documents in /usr/share/doc
493 various examples for users and programmers
495 firmware images loaded by userland programs
497 ASCII text files used by various games
499 known trusted and revoked keys.
500 .Bl -tag -width Fl -compact
514 miscellaneous system-wide ASCII text files
515 .Bl -tag -width Fl -compact
519 terminal characteristics database;
528 national language support files;
532 data files for security policies such as
540 (dot) files for new accounts
542 MIBs, example files and tree definitions for the SNMP daemon.
543 .Bl -tag -width Fl -compact
545 tree definition files for use with
551 files used by syscons;
554 .Bl -tag -width Fl -compact
562 console keyboard maps;
571 tab description files for a variety of terminals; used in
576 localization support and utilities for
582 .Bl -tag -width Fl -compact
590 console keyboard maps;
596 .\" console screen maps
599 timezone configuration information;
606 third-party, and/or local source files
608 .Bl -tag -width "kerberos5/" -compact
610 source code for files in /bin
612 utilities covered by the Common Development and Distribution License
614 source code for contributed software
616 source code for contributed cryptography software
618 source code for files in
621 utilities covered by the GNU General Public License
623 source code for files in
626 build infrastructure for Kerberos version 5
628 source code for files in
633 source code for files in
636 files required to produce a
640 source code for files in
643 source code for files in
646 build directory for files in
652 boot loader source code
655 .Bl -tag -width Fl -compact
657 AMD64 architecture support
659 ARM architecture support
661 ARMv8 architecture support
667 CDDL-licensed optional sources, including ZFS
678 i386 (32 bit) architecture support
680 main part of the kernel
682 MIPS architecture support
700 PowerPC/POWER architecture support
702 RISC-V architecture support
708 SPARC64 architecture support
714 code shared by AMD64 and i386 architectures
717 support for experimental DIRDEPS_BUILD
719 source code for files in
722 tools used for maintenance and testing of
725 source code for files in
728 source code for files in
741 multi-purpose log, temporary, transient, and spool files
743 .Bl -tag -width "defaults/" -compact
745 system accounting files
747 .Bl -tag -width Fl -compact
749 execution accounting file;
755 timed command scheduling files;
759 .Bl -tag -width Fl -compact
761 directory containing job files
763 directory containing output spool files
767 miscellaneous backup files
769 miscellaneous cached files
771 .Bl -tag -width Fl -compact
778 default directory to store kernel crash dumps; see
787 .Bl -tag -width Fl -compact
795 miscellaneous automatically generated system-specific database files
797 empty directory for use by programs that need a specifically empty directory.
800 for privilege separation.
802 miscellaneous game status and score files
804 Kerberos server databases; see
807 miscellaneous system log files
809 .Bl -tag -width Fl -compact
823 system messages database;
827 temporary home of files preserved after an accidental death
832 file system quota information files
834 system information files describing various info about
835 system since it was booted
837 .Bl -tag -width Fl -compact
841 group for command connection sockets; see
844 database of current users;
857 miscellaneous printer and mail system spooling directories
859 .Bl -tag -width Fl -compact
861 undelivered submission mail queue;
865 commonly ~ftp; the anonymous ftp root directory
867 undelivered mail queue;
871 line printer spooling directories
875 temporary files that are kept between system reboots
877 .Bl -tag -width Fl -compact
879 the directory where recovery files are stored
887 This manual page documents the default
889 file system layout, but
890 the actual hierarchy on a given system is defined at the system
891 administrator's discretion.
892 A well-maintained installation will include a customized version of
909 manual page appeared in