











                           44..44BBSSDD


                  SSyysstteemm MMaannaaggeerr''ss MMaannuuaall



                           ((SSMMMM))




















































Now  in its twentieth year, the USENIX Association, the UNIX
and Advanced Computing Systems  professional  and  technical
organization,  is a not-for-profit membership association of
individuals and institutions with an interest  in  UNIX  and
UNIX-like  systems,  and,  by extension, C++, X windows, and
other advanced tools and technologies.

USENIX and its members are dedicated to:

+o    fostering innovation  and  communicating  research  and
     technological developments,

+o    sharing  ideas  and  experience relevant to UNIX, UNIX-
     related, and advanced computing systems, and

+o    providing a neutral forum for the exercise of  critical
     thought and airing of technical issues.

USENIX publishes a journal (CCoommppuuttiinngg SSyysstteemmss), a newsletter
(_;_l_o_g_i_n_:), Proceedings from  its  frequent  Conferences  and
Symposia, and a Book Series.

SAGE,  The Systems Administrators Guild, a Special Technical
Group with the  USENIX  Association,  is  dedicated  to  the
advancement of system administration as a profession.

SAGE brings together systems managers and administrators to:

+o    propagate knowledge of good professional practice,

+o    recruit talented individuals to the profession,

+o    recognize individuals who  attain  professional  excel-
     lence,

+o    foster  technical  development  and  share solutions to
     technical problems, and

+o    communicate in an organized voice with  users,  manage-
     ment, and vendors on system administration topics.





























                           44..44BBSSDD


                  SSyysstteemm MMaannaaggeerr''ss MMaannuuaall



                           ((SSMMMM))








               BBeerrkkeelleeyy SSooffttwwaarree DDiissttrriibbuuttiioonn


                        AApprriill,, 11999944








              CCoommppuutteerr SSyysstteemmss RReesseeaarrcchh GGrroouupp

            UUnniivveerrssiittyy ooff CCaalliiffoorrnniiaa aatt BBeerrkkeelleeyy

















                 AA UUSSEENNIIXX AAssssoocciiaattiioonn BBooookk
                OO''RReeiillllyy && AAssssoocciiaatteess,, IInncc..
                 110033 MMoorrrriiss SSttrreeeett,, SSuuiittee AA












                    SSeebbaassttooppooll,, CCAA 9944557722

































































First Printing, 1994
Second Printing, 1995


Copyright  1979,  1980,  1983, 1986, 1988, 1989, 1991, 1992,
1993, 1994 The Regents of the University of California.  All
rights reserved.


Other  than  the  specific manual pages and documents listed
below as copyrighted by AT&T, redistribution and use of this
manual in source and binary forms, with or without modifica-
tion, are permitted provided that the  following  conditions
are met:

1)   Redistributions  of  this  manual must retain the copy-
     right notices on this page, this list of conditions and
     the following disclaimer.

2)   Software  or  documentation  that  incorporates part of
     this manual must reproduce  the  copyright  notices  on
     this  page,  this  list of conditions and the following
     disclaimer in the documentation and/or other  materials
     provided with the distribution.

3)   All advertising materials mentioning features or use of
     this software must display the  following  acknowledge-
     ment: ``This product includes software developed by the
     University of California, Berkeley  and  its  contribu-
     tors.''

4)   Neither the name of the University nor the names of its
     contributors may be used to endorse or promote products
     derived from this software without specific prior writ-
     ten permission.

TTHHIISS SSOOFFTTWWAARREE IISS PPRROOVVIIDDEEDD BBYY TTHHEE  RREEGGEENNTTSS  AANNDD  CCOONNTTRRIIBBUUTTOORRSS
````AASS  IISS'''' AANNDD AANNYY EEXXPPRREESSSS OORR IIMMPPLLIIEEDD WWAARRRRAANNTTIIEESS,, IINNCCLLUUDDIINNGG,,
BBUUTT NNOOTT LLIIMMIITTEEDD TTOO,, TTHHEE IIMMPPLLIIEEDD WWAARRRRAANNTTIIEESS OOFF  MMEERRCCHHAANNTTAABBIILL--
IITTYY AANNDD FFIITTNNEESSSS FFOORR AA PPAARRTTIICCUULLAARR PPUURRPPOOSSEE AARREE DDIISSCCLLAAIIMMEEDD..  IINN
NNOO EEVVEENNTT SSHHAALLLL TTHHEE RREEGGEENNTTSS OORR CCOONNTTRRIIBBUUTTOORRSS BBEE LLIIAABBLLEE FFOORR AANNYY
DDIIRREECCTT,,  IINNDDIIRREECCTT,, IINNCCIIDDEENNTTAALL,, SSPPEECCIIAALL,, EEXXEEMMPPLLAARRYY,, OORR CCOONNSSEE--
QQUUEENNTTIIAALL DDAAMMAAGGEESS ((IINNCCLLUUDDIINNGG,, BBUUTT NNOOTT LLIIMMIITTEEDD TTOO,, PPRROOCCUURREEMMEENNTT
OOFF SSUUBBSSTTIITTUUTTEE GGOOOODDSS OORR SSEERRVVIICCEESS;; LLOOSSSS OOFF UUSSEE,, DDAATTAA,, OORR PPRROOFF--
IITTSS;; OORR BBUUSSIINNEESSSS IINNTTEERRRRUUPPTTIIOONN)) HHOOWWEEVVEERR  CCAAUUSSEEDD  AANNDD  OONN  AANNYY
TTHHEEOORRYY  OOFF LLIIAABBIILLIITTYY,, WWHHEETTHHEERR IINN CCOONNTTRRAACCTT,, SSTTRRIICCTT LLIIAABBIILLIITTYY,,
OORR TTOORRTT ((IINNCCLLUUDDIINNGG NNEEGGLLIIGGEENNCCEE OORR OOTTHHEERRWWIISSEE)) AARRIISSIINNGG  IINN  AANNYY
WWAAYY  OOUUTT OOFF TTHHEE UUSSEE OOFF TTHHIISS SSOOFFTTWWAARREE,, EEVVEENN IIFF AADDVVIISSEEDD OOFF TTHHEE
PPOOSSSSIIBBIILLIITTYY OOFF SSUUCCHH DDAAMMAAGGEE..


The Institute of Electrical and  Electronics  Engineers  and
the American National Standards Committee X3, on Information
Processing Systems  have  given  us  permission  to  reprint












portions of their documentation.

In  the following statement, the phrase ``this text'' refers
to portions of the system documentation.

``Portions of this text  are  reprinted  and  reproduced  in
electronic  form  in  4.4BSD from IEEE Std 1003.1-1988, IEEE
Standard Portable Operating System  Interface  for  Computer
Environments  (POSIX),  copyright  1988  by the Institute of
Electrical and Electronics Engineers, Inc.  In the event  of
any discrepancy between these versions and the original IEEE
Standard, the original IEEE Standard is  the  referee  docu-
ment.''

In  the  following  statement,  the phrase ``This material''
refers to portions of the system documentation.

``This material is reproduced with permission from  American
National  Standards  Committee X3, on Information Processing
Systems.   Computer  and  Business  Equipment  Manufacturers
Association  (CBEMA), 311 First St., NW, Suite 500, Washing-
ton, DC 20001-2178.  The developmental work  of  Programming
Language C was completed by the X3J11 Technical Committee.''


Manual pages cron.8, icheck.8, ncheck.8, and sa.8 and  docu-
ments SMM:15, 16, and 17 are copyright 1979, AT&T Bell Labo-
ratories, Incorporated.  Document SMM:14 is  a  modification
of an earlier document that is copyrighted 1979 by AT&T Bell
Laboratories, Incorporated.  Holders of  UNIXTM/32V,  System
III,  or  System  V  software licenses are permitted to copy
these documents, or any portion of them,  as  necessary  for
licensed use of the software, provided this copyright notice
and statement of permission are included.


The views and conclusions contained in this manual are those
of the authors and should not be interpreted as representing
official policies,  either  expressed  or  implied,  of  the
Regents of the University of California.


The  4.4BSD  Daemon  used  on the cover is copyright 1994 by
Marshall Kirk McKusick and is reproduced with permission.
This book was printed and bound  in  the  United  States  of
America.
Distributed by O'Reilly & Associates, Inc.


[recycle logo]  This book is printed on acid-free paper with
                50% recycled content,  10-13%  post-consumer
                waste. O'Reilly & Associates is committed to
                using paper with the highest  recycled  con-
                tent available consistent with high quality.












ISBN: 1-56592-080-5






































































                          CCoonntteennttss



Introduction                                             vii


List of Manual Pages                                      ix


Permuted Index                                         xxxix


Reference Manual Section 8                         tabbed M8

     Section 8 of the UNIX Programmer's Manual contains
     information  related to system operation, adminis-
     tration, and maintenance.


Installing and Operating 4.4BSD                     tabbed 1

     The definitive reference document for those  occa-
     sions  when you find you need to start over again.


Building 4.4BSD Kernels with _C_o_n_f_i_g                 tabbed 2

     In-depth discussions of the use and  operation  of
     the _c_o_n_f_i_g program, and how to build your very own
     Unix kernel.


Fsck - The UNIX File System Check Program           tabbed 3

     A reference document for using  the  _f_s_c_k  program
     during times of file system distress.


Disc Quotas in a UNIX Environment                   tabbed 4

     A  light introduction to the techniques for limit-
     ing the use of disc resources.


A Fast File System for UNIX                         tabbed 5

     A description of the 4.4BSD file system  organiza-
     tion, design and implementation.









Contents                                              - ix -


The 4.4BSD NFS Implementation                       tabbed 6

     An overview of the design, implementation, and use
     of NFS on 4.4BSD.


Line Printer Spooler Manual                         tabbed 7

     This document describes the structure and  instal-
     lation  procedure  for  the  line printer spooling
     system.


Sendmail Installation and Operation Guide           tabbed 8

     The last word  in  installing  and  operating  the
     _s_e_n_d_m_a_i_l program.


Sendmail - An Internetwork Mail Router              tabbed 9

     An overview document on the design and implementa-
     tion of _s_e_n_d_m_a_i_l.


Name Server Operations Guide for BIND              tabbed 10

     Setting up and  operating  the  name  to  Internet
     addressing  software.   If you have a network this
     will be of interest.


Timed Installation and Operation Guide             tabbed 11

     Describes how  to  maintain  time  synchronization
     between machines in a local network.


The Berkeley UNIX Time Synchronization Protocol    tabbed 12

     The  protocols  and  algorithms used by timed, the
     network time synchronization daemon.


AMD - The 4.4BSD Automounter                       tabbed 13

     Automatically mounting file systems on demand.


Installation and Operation of UUCP                 tabbed 14

     Describes the  implementation  of  uucp;  for  the
     installer and administrator.










- x -                                               Contents


A Dial-Up Network of UNIX Systems                  tabbed 15

     Describes  UUCP, a program for communicating files
     between UNIX systems.


On the Security of UNIX                            tabbed 16

     Hints on how to break UNIX, and how to avoid  your
     system being broken.


Password Security - A Case History                 tabbed 17

     How  the  bad  guys  used  to be able to break the
     password algorithm, and why they  cannot  now  (at
     least not so easily).


Networking Implementation Notes, 4.4BSD Edition    tabbed 18

     A  concise  description  of  the system interfaces
     used within the networking subsystem.


The PERL Programming Language                      tabbed 19

     The Practical Extraction and  Report  Language  is
     ideal   for   writing  those  pesky  adminitration
     scripts.


List of Documents                          inside back cover

































                          IInnttrroodduuccttiioonn



The documentation for 4.4BSD is in a format similar  to  the
one  used  for the 4.2BSD and 4.3BSD manuals.  It is divided
into three sets; each set consists of one or  more  volumes.
The  abbreviations for the volume names are listed in square
brackets; the abbreviations  for  the  manual  sections  are
listed in parenthesis.

     I. User's Documents
          User's Reference Manual [URM]
               Commands (1)
               Games (6)
               Macro packages and language conventions (7)
          User's Supplementary Documents [USD]
               Getting Started
               Basic Utilities
               Communicating with the World
               Text Editing
               Document Preparation
               Amusements

     II. Programmer's Documents
          Programmer's Reference Manual [PRM]
               System calls (2)
               Subroutines (3)
               Special files (4)
               File formats and conventions (5)
          Programmer's Supplementary Documents [PSD]
               Documents of Historic Interest
               Languages in common use
               Programming Tools
               Programming Libraries
               General Reference

     III. System Manager's Manual [SMM]
          Maintenance commands (8)
          System Installation and Administration


References  to  individual  documents  are  given  as ``vol-
ume:document'', thus USD:1 refers to the first  document  in
the  ``User's Supplementary Documents''.  References to man-
ual pages are given as ``_n_a_m_e(section)'' thus  _s_h(1)  refers
to the shell manual entry in section 1.

The  manual  pages  give descriptions of the features of the
4.4BSD system, as developed at the University of  California
at  Berkeley.  They do not attempt to provide perspective or
tutorial information about the 4.4BSD operating system,  its
facilities,  or  its  implementation.   Various documents on
those  topics   are   contained   in   the   ``UNIX   User's









- xii -                                         Introduction


Supplementary  Documents''  (USD),  the  ``UNIX Programmer's
Supplementary Documents'' (PSD), and ``UNIX System Manager's
Manual''  (SMM).   In  particular, for an overview see ``The
UNIX Time-Sharing System'' (PSD:1) by Ritchie and  Thompson;
for  a  tutorial  see  ``UNIX  for  Beginners''  (USD:1)  by
Kernighan, and for an guide to the new features of this lat-
est  version,  see  ``Berkeley  Software Architecture Manual
(4.4 Edition)'' (PSD:5).

Within the area it  surveys,  this  volume  attempts  to  be
timely,  complete  and concise.  Where the latter two objec-
tives conflict, the obvious is often left unsaid in favor of
brevity.   It  is intended that each program be described as
it is, not as it should be.   Inevitably,  this  means  that
various sections will soon be out of date.

Commands are programs intended to be invoked directly by the
user, in contrast to subroutines, that are  intended  to  be
called  by the user's programs.  User commands are described
in URM section 1.  Commands generally  reside  in  directory
_/_b_i_n  (for  _b_i_nary  programs).  Some programs also reside in
_/_u_s_r_/_b_i_n_, to save space  in  _/_b_i_n_.   These  directories  are
searched  automatically  by the command interpreters.  Addi-
tional directories that may be of interest include _/_u_s_r_/_c_o_n_-
_t_r_i_b_/_b_i_n_, which has contributed software _/_u_s_r_/_o_l_d_/_b_i_n_, which
has  old   but   sometimes   still   useful   software   and
_/_u_s_r_/_l_o_c_a_l_/_b_i_n_,  which contains software local to your site.

Games have been relegated to URM section 6  and  _/_u_s_r_/_g_a_m_e_s_,
to  keep  them from contaminating the more staid information
of URM section 1.

Miscellaneous collection of information necessary for  writ-
ing  in  various  specialized  languages  such  as character
codes, macro packages for typesetting, etc is  contained  in
URM section 7.

System  calls  are  entries into the BSD kernel.  The system
call interface is identical to a C language procedure  call;
the  equivalent C procedures are described in PRM section 2.

An  assortment  of  subroutines  is  available;   they   are
described  in PRM section 3.  The primary libraries in which
they are kept are described in _i_n_t_r_o(3).  The functions  are
described in terms of C.

PRM  section  4 discusses the characteristics of each system
``file'' that refers to an I/O device.  The  names  in  this
section  refer  to  the HP300 device names for the hardware,
instead of the names of the special files themselves.

The file formats and conventions (PRM section  5)  documents
the structure of particular kinds of files; for example, the
form of the output of the loader  and  assembler  is  given.









Introduction                                        - xiii -


Excluded are files used by only one command, for example the
assembler's intermediate files.

Commands and procedures intended for use  primarily  by  the
system  administrator  are  described in SMM section 8.  The
files described here are almost all kept  in  the  directory
_/_e_t_c_.   The  system administration binaries reside in _/_s_b_i_n_,
and _/_u_s_r_/_s_b_i_n_.

Each section consists of independent entries of a page or so
each.   The name of the entry is in the upper corners of its
pages, together with the  section  number.   Entries  within
each  section  are  alphabetized.   The page numbers of each
entry start at 1; it is infeasible to  number  consecutively
the  pages  of  a  document like this that is republished in
many variant forms.

All entries are based on a common format;  not  all  subsec-
tions always appear.

     The  _n_a_m_e  subsection lists the exact names of the com-
     mands and subroutines covered under the entry and gives
     a short description of their purpose.

     The  _s_y_n_o_p_s_i_s  summarizes  the use of the program being
     described.  A few conventions are used, particularly in
     the Commands subsection:

          BBoollddffaaccee  words  are  considered literals, and are
          typed just as they appear.

          Square brackets [ ] around an argument  show  that
          the  argument  is  optional.   When an argument is
          given as ``name'', it  always  refers  to  a  file
          name.

          Ellipses  ``...'' are used to show that the previ-
          ous argument-prototype may be repeated.

          A final convention is used by the  commands  them-
          selves.   An  argument beginning with a minus sign
          ``-'' usually means that it is an  option-specify-
          ing  argument,  even  if  it appears in a position
          where a file name could appear.  Therefore, it  is
          unwise to have files whose names begin with ``-''.

     The _d_e_s_c_r_i_p_t_i_o_n subsection discusses in detail the sub-
     ject at hand.

     The  _f_i_l_e_s subsection gives the names of files that are
     built into the program.

     A _s_e_e _a_l_s_o subsection gives pointers to related  infor-
     mation.









- xiv -                                         Introduction


     A _d_i_a_g_n_o_s_t_i_c_s subsection discusses the diagnostic indi-
     cations  that  may  be  produced.   Messages  that  are
     intended to be self-explanatory are not listed.

     The  _b_u_g_s  subsection  gives  known  bugs and sometimes
     deficiencies.  Occasionally the suggested fix  is  also
     described.

At  the  beginning  of URM, PRM, and SSM is a List of Manual
Pages, organized by section and alphabetically  within  each
section,  and  a  Permuted  Index  derived  from  that List.
Within each index entry, the title of the writeup  to  which
it  refers  is followed by the appropriate section number in
parentheses.  This fact is important because there  is  con-
siderable name duplication among the sections, arising prin-
cipally from commands that exist only to exercise a particu-
lar  system  call.  Finally, there is a list of documents on
the inside back cover of each volume.
















































                    LLiisstt ooff MMaannuuaall PPaaggeess

11.. CCoommmmaannddss aanndd AApppplliiccaattiioonn PPrrooggrraammss

22.. SSyysstteemm CCaallllss

33.. CC LLiibbrraarryy SSuubbrroouuttiinneess

44.. SSppeecciiaall FFiilleess

55.. FFiillee FFoorrmmaattss

66.. GGaammeess

77.. MMiisscceellllaanneeoouuss

88.. SSyysstteemm MMaaiinntteennaannccee








































Section 8                                 System Maintenance





- xvi -                                         Manual Pages



























































System Maintenance                                 Section 8









                       PPeerrmmuutteedd IInnddeexx























































4.4BSD                                            April 1994


