Provided by: dictd_1.13.1+dfsg-1build1_amd64 bug

NAME

       dictd - a dictionary database server

SYNOPSIS

       dictd [options]

DESCRIPTION

       dictd  is  a  server  for  the  Dictionary Server Protocol (DICT), a TCP transaction based
       query/response protocol that allows a client to access dictionary definitions from  a  set
       of natural language dictionary databases.

       For security reasons, dictd drops root permissions after startup.  If user dictd exists on
       the system, the daemon will run as that user, group dictd, otherwise it will run  as  user
       nobody, group nobody or nogroup (depending on the operating system distribution).

       Since  startup time is significant, the server is designed to run continuously, and should
       not be run from inetd(8).  (However, with a fast processor, it is feasible to do so.)

       Databases are distributed separately from the server.

       By default, dictd assumes that  the  index  files  are  sorted  alphabetically,  and  only
       alphanumeric  characters  from  the  7-bit  ASCII character set are used for search.  This
       default may be overridden  by  a  header  in  the  data  file.   The  only  such  features
       implemented  at  this  time  are the headers "00-database-allchars" which tells dictd that
       non-alphanumeric characters may also be used for  search,  the  header  "00-database-utf8"
       which indicates that the database uses utf8 encoding, and the "00-database-8bit-new" which
       indicates that the database is encoded and sorted according to a locale that uses an 8-bit
       encoding.

BACKGROUND

       For  many years, the Internet community has relied on the "webster" protocol for access to
       natural language definitions.  The webster protocol supports access to a single dictionary
       and (optionally) to a single thesaurus.  In recent years, the number of publicly available
       webster servers on the Internet has dramatically decreased.

       Fortunately, several freely-distributable dictionaries and lexicons have  recently  become
       available  on  the  Internet.   However,  these  freely-distributable  databases  are  not
       accessible via a uniform interface, and are not accessible from a single site.   They  are
       often small and incomplete individually, but would collectively provide an interesting and
       useful database of English words.  Examples include the Jargon file, the WordNet database,
       MICRA's  version  of the 1913 Webster's Revised Unabridged Dictionary, and the Free Online
       Dictionary of Computing.  (See the DICT  protocol  specification  (RFC)  for  references.)
       Translating  and  non-English  dictionaries  are also becoming available (for example, the
       FOLDOC dictionary is being translated into Spanish).

       The webster protocol is not suitable for providing access to a large  number  of  separate
       dictionary databases, and extensions to the current webster protocol were not felt to be a
       clean solution to the dictionary database problem.

       The DICT protocol is designed to provide access to multiple databases.   Word  definitions
       can  be  requested,  the  word  index  can  be  searched  (using an easily extended set of
       algorithms), information about the server  can  be  provided  (e.g.,  which  index  search
       strategies  are  supported,  or  which  databases  are available), and information about a
       database can  be  provided  (e.g.,  copyright,  citation,  or  distribution  information).
       Further, the DICT protocol has hooks that can be used to restrict access to some or all of
       the databases.

       dictd(8) is a server that implements the DICT protocol.  Bret Martin  implemented  another
       server,  and  several  people  (including  Bret  and myself) have implemented clients in a
       variety of languages.

OPTIONS

       -V or --version
              Display version information.

       --license
              Display copyright and license information.

       -h or --help
              Display help information.

       -v or --verbose or  -dverbose
              Be verbose.

       -c file or --config file
              Specify configuration file.  The default is  /etc/dictd/dictd.conf  ,  but  may  be
              changed in the defs.h file at compile time (DICTD_CONFIG_FILE).

       -p port or --port port
              Overrides   the   keyword   port   in  Global  Settings  Specification  section  of
              configuration file.

       -i or --inetd
              Communicate on standard input/output, suitable for use from inetd.   Although,  due
              to  its  rather large startup time, this daemon was not intended to run from inetd,
              with a fast processor it is feasible to do so. This  option  also  implies  --fast-
              start.

       --pp prog
              Sets   a   preprocessor  for  configuration  file.   like    m4  or    cpp  .   See
              examples/dictd_complex.conf file from distribution. By default  configuration  file
              is parsed without preprocessor.

       --depth length
              Overrides   the   keyword   depth  in  Global  Settings  Specification  section  of
              configuration file.

       --delay seconds
              Overrides  the  keyword  delay  in  Global  Settings   Specification   section   of
              configuration file.

       --facility facility
              The   same   as   syslog_facility  keyword  in  Global  Settings  Specification  of
              configuration files.

       -f or --force
              Force the daemon to start even if an instance of the  daemon  is  already  running.
              (This  is of little value unless a non-default port is specified with -p, since, if
              one instance is bound to a port, the second one fails when it can not bind  to  the
              port.)

       --limit children
              Overrides   the   keyword   limit  in  Global  Settings  Specification  section  of
              configuration file.

       --listen-to host
              Overrides the  keyword  listen_to  in  Global  Settings  Specification  section  of
              configuration file.

       --address-family family
              Overrides  the  keyword  address_family in Global Settings Specification section of
              configuration file.

       --locale locale
              Overrides  the  keyword  locale  in  Global  Settings  Specification   section   of
              configuration file.

       -s     The same as syslog keyword in Global Settings Specification of configuration files.

       -L file or --logfile file
              The  same  as  log_file  keyword  in Global Settings Specification of configuration
              files.

       --pid-file file
              The same as pid_file keyword in  Global  Settings  Specification  of  configuration
              files.

       -m minutes  or --mark minutes
              Overrides  the  keyword  timestamp  in  Global  Settings  Specification  section of
              configuration file.

       --default-strategy strategy
              Overrides the keyword default_strategy in Global Settings Specification section  of
              configuration file.

       --without-strategy strat1,strat2,...
              The   same   as  without_strategy  keyword  in  Global  Settings  Specification  of
              configuration files.

       --add-strategy strategy_name:description
              The same as add_strategy keyword in Global Settings Specification of  configuration
              files.

       --fast-start
              The  same  as  fast_start keyword in Global Settings Specification of configuration
              files.

       --without-mmap
              The same as without_mmap keyword in Global Settings Specification of  configuration
              files.

       --stdin2stdout
              When  applied  with  --inetd, each command obtained from stdin is output to stdout.
              This option is useful for debugging.

       -l option or --log option
              The same as log_option keyword in Global Settings  Specification  of  configuration
              files.

       -d option
              The  same as debug_option keyword in Global Settings Specification of configuration
              files.

CONFIGURATION FILE

       Introduction
              The configuration file defaults to /etc/dictd/dictd.conf but can  be  specified  on
              the command line with the -c option (see above).

              The  configuration file is read into memory at startup, and is not referenced again
              by dictd unless a signal 1 (SIGHUP) is received, which will cause dictd  to  reread
              the configuration file.

              The  file is divided into sections.  The Access Section should come first, followed
              by the Database Section, and the User Section.  The Database Section  is  required;
              the others are optional, but they must be in the order listed here.

       Syntax The  following  keywords  are  valid  in a configuration file: access, allow, deny,
              group, database, data, index, filter, prefilter, postfilter, name,  include,  user,
              authonly, site.  Keywords are case sensitive.  String arguments that contain spaces
              should be surrounded by  double  quotes.   Without  quoting,  strings  may  contain
              alphanumeric  characters  and  _,  -,  .,  and  *,  but not spaces.  Strings can be
              continued between lines.  \", \\, \n, \<NL> are treated as double quote, backslash,
              new  line  and no symbol respectively.  Comments start with # and extend to the end
              of the line.

       Global Settings Section

              global { global settings specification }
                     Used to set global dictd setting such as log file, syslog  facility,  locale
                     and so on.

              EXAMPLE:
                     See examples/dictd4.conf file from the distribution.

       Access Section

              access { access specification }
                     This  section  contains  access  restrictions  for the server and all of the
                     databases collectively.  Per-database control is specified in  the  Database
                     Section.

              EXAMPLE:
                     See examples/dictd3.conf file from the distribution.

       Database Section

              database string { database specification }
                     The  string specifies the name of the database (e.g., wn or web1913).  (This
                     is an arbitrary name selected by the administrator, and is  not  necessarily
                     related to the file name or any name listed in the data file.  A short, easy
                     to type name is often selected for easy use with dict -d.)

                     EXAMPLE: See examples/dictd*.conf files from the distribution.

                     NOTE: If the files specified in the database specification do not  exist  on
                     the system, dictd may silently fail.

              database_virtual string { virtual database specification }
                     This  section specifies the virtual database.  The string specifies the name
                     of the database (e.g., en-ru or fren).

                     EXAMPLE:  See  examples/dictd_virtual.conf  or   examples/dictd_complex.conf
                     files from the distribution.

              database_plugin string { plugin specification }
                     This  section  specifies  the  plugin.  The string specifies the name of the
                     database.

                     EXAMPLE: See examples/dictd_plugin_dbi.conf  or  examples/dictd_complex.conf
                     files from the distribution.

              database_mime string { mime specification }
                     Traditionally, databases created for dictd contained plain text only because
                     dictd releases before 1.10.0 didn't have full support of OPTION MIME  option
                     (consult  with RFC-2229).  This section describes the special database which
                     behaves differently depending on whether OPTION MIME  command  was  received
                     from client or was not, i.e. the database created by this section allows one
                     to return to the client either a plain text or specially  formatted  content
                     depending  on  whether  DICT  client supports (or wants to receive) MIMEized
                     content or doesn't.  The string specifies the name of the database.

                     NOTE: All this is about DEFINE command only.  MATCH, SHOW  DB,  SHOW  STRAT,
                     SHOW  INFO,  SHOW SERVER and HELP commands return texts prepended with empty
                     line only.

                     EXAMPLE: See examples/dictd_mime.conf file from the distribution.

              database_exit
                     Excludes following databases from the '*' database.  By  default  '*'  means
                     all  databases  available.   Look  at 'examples/dictd_virtual.conf' file for
                     example configuration.

                     NOTE: If you use 'virtual' dictionaries,  you  should  use  this  directive,
                     otherwise you will search the same dictionary twice.

              User Section

                     user string string
                            The  first  string  specifies  the  username,  and  the second string
                            specifies the shared secret for this username.  When the AUTH command
                            is used, the client will provide the username and a hashed version of
                            the shared secret.  If the shared secret matches, the user is said to
                            have  authenticated,  and  will have access to databases whose access
                            specifications allow  that  user  (by  name,  or  by  wildcard).   If
                            present,  this  section  must  appear last in the configuration file.
                            There may be many user entries.  The shared  secret  should  be  kept
                            secret,  as  anyone  who  has  access  to  it  can  access the shared
                            databases (assuming access is not denied by domain name).

              Access Specification
                     Access specifications may occur in the Access Section  or  in  the  Database
                     Section.  The access specification will be described here.

                     For  allow,  deny,  and authonly, a star (*) may be used as a wild card that
                     matches any number of characters.  A question mark (?)  may  be  used  as  a
                     wildcard  that  matches a single character.  For example, 10.0.0.* and *.edu
                     are valid strings.

                     Further, a range of IP addresses and an IP address followed by a netmask may
                     be  specified.   For example, 10.0.0.0:10.0.0.255, 10.0.0.0/24, and 10.0.0.*
                     all specify the same range of IP numbers.  Notation cannot  be  combined  on
                     the  same  line.  If the notation does not make sense, access will be denied
                     by default.  Use the --debug auth option to debug related problems.

                     Note that these specifications take only one string per specification  line.
                     However, you can have multiple lines of each type.

                     The syntax is as follows:

                     allow string
                            The  string  specifies  a  domain name or IP address which is allowed
                            access to the server (in the Access Section) or to a database (in the
                            Database  Section).   Note that more than one string is not permitted
                            for a single "allow" line,  but  more  than  one  "allow"  lines  are
                            permitted in the configuration file.

                     deny string
                            The  string  specifies  a  domain  name or IP address which is denied
                            access to the server (in the Access Section) or to a database (in the
                            Database  Section).   Note  that  if reverse DNS is not working, then
                            only the IP number will be checked.  Therefore, it  is  essential  to
                            deny networks based on IP number, since a denial based on domain name
                            may not always be checked.

                     authonly string
                            This form is only useful in the Access Section.  The string specifies
                            a domain name or IP address which is allowed access to the server but
                            not to any of the databases.  All commands are valid  except  DEFINE,
                            MATCH,  and  SHOW DB.  More specifically AUTH is a valid command, and
                            commands which access the databases are not allowed.

                     user string
                            This form is  only  useful  in  the  Database  Section.   The  string
                            specifies  a username that is allowed to access this database after a
                            successful AUTH command is executed.

       Global Settings Specification
              This section describes the following parameters:

              port string_or_number
                     Specifies the port or service name (e.g., 2628).  The default  is  2628,  as
                     specified in the DICT Protocol RFC, but may be changed in the defs.h file at
                     compile time (DICT_DEFAULT_SERVICE).

              site string
                     Used to specify the filename for the site information file, a flat text file
                     which will be displayed in response to the SHOW SERVER command.

                     EXAMPLE: See examples/dictd4.conf file from the distribution.

              site_no_banner boolean
                     By  default  SHOW SERVER command outputs information about dictd version and
                     an operating system type.  This option disables this.

              site_no_uptime boolean
                     By default SHOW SERVER command outputs information about uptime of dictd , a
                     number  of  forks  since  startup  and forks per hour.  This option disables
                     this.

              site_no_dblist boolean
                     By default SHOW SERVER command outputs internal information about databases,
                     such  as  a number of headwords, index size and so on.  This option disables
                     this.

              delay number
                     Specifies the number of seconds a client may be idle before the server  will
                     close  the  connection.   Idle  time is defined to be the time the server is
                     waiting for input and does not include the time the server spends  searching
                     the database. The default is 0 seconds (no limit), but may be changed in the
                     defs.h file at compile time (DICT_DEFAULT_DELAY).

                     NOTE: Setting delay option disables limit_time  option.  Only  one  of  them
                     (last specified in dictd.conf ) is in effect.

                     NOTE:  Connections  are  closed  without  warning  since  no  provision  for
                     premature connection termination is specified in the DICT protocol RFC.

              depth number
                     Specify the queue length for listen(2).  Specifies  the  number  of  pending
                     socket connections which are queued by the operating system.  Some operating
                     systems may silently limit this value  to  5  (older  BSD  systems)  or  128
                     (Linux).  The default is 10 but may be changed in the defs.h file at compile
                     time (DICT_QUEUE_DEPTH).

              limit_childs number
                     Specifies the number of daemons that may be  running  simultaneously.   Each
                     daemon   services  a  single  connection.   If  the  limit  is  exceeded,  a
                     (serialized) connection will be made by the server process, and  a  response
                     code  420 (server temporarily unavailable) will be sent to the client.  This
                     parameter should be adjusted  to  prevent  the  server  machine  from  being
                     overloaded  by  dict clients, but should not be set so low that many clients
                     are denied useful connections. The default is 100, but may be changed in the
                     defs.h file at compile time (DICT_DAEMON_LIMIT_CHILDS).

              limit number
                     Synonym for limit_childs.  For backward compatibility only.

              limit_matches number
                     Specifies the maximum number of matches that can be returned by MATCH query.
                     Zero means no limit. The default is 2000.

              limit_definitions number
                     Specifies the maximum number of definitions that can be returned  by  DEFINE
                     query. Zero means no limit. The default is 200.

              limit_time number
                     Specifies  the  number of seconds a client may talk to the server before the
                     server will close the connection.  The default is 600 seconds (10  minutes),
                     but    may    be    changed   in   the   defs.h   file   at   compile   time
                     (DICT_DEFAULT_LIMIT_TIME).

                     NOTE: Setting limit_time option disables delay  option.  Only  one  of  them
                     (last specified in dictd.conf ) is in effect.

                     NOTE:  Connections  are  closed  without  warning  since  no  provision  for
                     premature connection termination is specified in the DICT protocol RFC.

              limit_queries number
                     Specifies the number of queries (MATCH, DEFINE, SHOW DB etc.)   that  client
                     may  send  to  the server before the server will close the connection.  Zero
                     means no limit.  The default is 2000, but may be changed in the defs.h  file
                     at compile time (DICT_DEFAULT_LIMIT_QUERIES).

              timestamp number
                     How  often  a  timestamp should be logged (int minutes).  (This is effective
                     only if logging has been enabled with  the  -s  or  -L  option,  or  with  a
                     debugging option.)

              log_option option
                     Specify  a  logging  option.   This  is  effective  only if logging has been
                     enabled with the -s or -L option or in configuration file, or logging to the
                     console  has been activated with a debugging option (e.g., --debug nodetach.
                     Only one option may be set with each invocation  of  this  option;  however,
                     multiple  invocations  of  this  option may be made in configuration file or
                     dictd command line.  For instance:
                     dictd -s --log stats --log found --log notfound
                     is a valid command line, and sets three logging options.

                     Some of the more verbose logging options are used  primarily  for  debugging
                     the server code, and are not practical for normal use.

                     server Log server diagnostics.  This is extremely verbose.

                     connect
                            Log all connections.

                     stats  Log all children terminations.

                     command
                            Log all commands.  This is extremely verbose.

                     client Log results of CLIENT command.

                     found  Log all words found in the databases.

                     notfound
                            Log all words not found in the databases.

                     timestamp
                            When  logging  to a file, use a full timestamp like that which syslog
                            would produce.  Otherwise, no timestamp is  made,  making  the  files
                            shorter.

                     host   Log name of foreign host.

                     auth   Log authentication failures.

                     min    Set a minimal number of options.  If logging is activated (to a file,
                            or via syslog), and no options are  set,  then  the  minimal  set  of
                            options  will  be  used.  If options are set, then only those options
                            specified will be used.

                     all    Set all of the options.

                     none   Clear all of the options.

                     To facilitate location of interesting information in the log  file,  entries
                     are  marked  with  initial  letters  indicating  the class of the line being
                     logged:

                     I      Information about the server, connections, or termination statistics.
                            These lines are generally not designed to be parsed automatically.

                     E      Error messages.

                     C      CLIENT command information.

                     D      Definitions found in the databases searched.

                     M      Matches found in the database searched.

                     N      Matches which were not found in the databases searched.

                     T      Trace of exact line sent by client.

                     A      Authentication information.

                     To preserve anonymity of the client, do not use the connect or host options.
                     Clients may or may not send host information using the CLIENT  command,  but
                     this should be an option that is selectable on the client side.

              debug_option string
                     Activate  a  debugging  option.   There  are  several, all of which are only
                     useful to developers.  They are documented here for  completeness.   A  list
                     can be obtained interactively by using -d with an illegal option.

                     verbose
                            The same as -v or --verbose.  Adds verbosity to other options.

                     scan   Debug the scanner for the configuration file.

                     parse  Debug the parser for the configuration file.

                     search Debug the character folding and binary search routines.

                     init   Report database initialization.

                     port   Log client-side port number to the log file.

                     lev    Debug Levenshtein search algorithm.

                     auth   Debug the authorization routines.

                     nodetach
                            Do  not  detach  as a background process.  Implies that a copy of the
                            log file will appear on the standard output.

                     nofork Do not fork  daemons  to  service  requests.   Be  a  single-threaded
                            server.  This option implies nodetach, and is most useful for using a
                            debugger to find the point at  which  daemon  processes  are  dumping
                            core.

                     alt    Debugs altcompare in index.c.

              locale string
                     Specifies the locale used for searching.  If no locale is specified, the "C"
                     locale is used.  The locale used for the server should be the same  as  that
                     used for dictfmt when the database was built (specifically, the locale under
                     which the index was sorted). The locale should be specified for  both  8-bit
                     and  UTF-8 formats. If locale contains utf8 or utf-8 substring, UTF-8 format
                     is expected.  Note that if your database is not in ASCII7 or  UTF-8  format,
                     then the dictd server will not be compliant to RFC 2229.

                     NOTE  If utf-8 or 8-bit dictionaries are included in the configuration file,
                     and the appropriate --locale has not been  specified,  dictd  will  fail  to
                     start.   This  implies  that  dictd  will  not run with both utf-8 and 8-bit
                     dictionaries in the configuration file.

              add_strategy strategy_name description
                     Adds strategy strategy_name with  the  description  description.   This  new
                     search   strategy   may  be  implemented  with  a  help  of  plugins.   Both
                     strategy_name and description are strings.

              default_strategy string
                     Set the server's  default  search  strategy  for  MATCH  search  type.   The
                     compiled-in  default  is 'lev'.  It is also possible to set default strategy
                     per  database.   See  default_strategy  keyword  in  Database  specification
                     section.

              disable_strategy string
                     Disable  specified strategies.  By default all implemented search strategies
                     are enabled.  It is also possible to disable strategies per  database.   See
                     disable_strategy keyword in Database specification section.

              listen_to host
                     Local  host  name  or  IP address for bind.  If unspecified or *, dictd will
                     bind to all interfaces.  Otherwise, dictd will bind to this address only.

              address_family family
                     If 4, address family is IPv4 (the default), if 6, address family is IPv6.

              syslog string
                     Log using the syslog(3) facility.

              syslog_facility string
                     Specifies the syslog facility to use.  The use of this option implies the -s
                     option  to  turn on logging via syslog.  When the operating system libraries
                     support SYSLOG_NAMES, the names used for this option should be those  listed
                     in  syslog.conf(5).   Otherwise,  the following names are used (assuming the
                     particular facility is defined in the header files): auth,  authpriv,  cron,
                     daemon,  ftp,  kern,  lpr,  mail,  news, syslog, user, uucp, local0, local1,
                     local2, local3, local4, local5, local6, and local7.

              log_file string
                     Specify the file for logging.  The filename specified is recomputed on  each
                     use using the strftime(3) call.  For example, a filename ending in ".%Y%m%d"
                     will write to log files ending in the year, month, and  date  that  the  log
                     entry was written.
                     NOTE:  If  dictd  does  not  have  write  permission  for this file, it will
                     silently fail.

              pid_file string
                     The specified filename will be created to contain the process id of the main
                     dictd process. The default is /var/run/dictd.pid

              fast_start
                     By  default,  dictd  creates (in memory) additional index to make the search
                     faster.  This option disables this behaviour and makes startup faster.

              without_mmap
                     do not use the mmap(2) function and read entire files into  memory  instead.
                     Use this option, if you know exactly what you are doing.

       Database Specification
              The database specification describes the database:

              data string
                     Specifies the filename for the flat text database.  If the filename does not
                     begin with '.' or '/', it is prepended with $datadir/. It is a compile  time
                     option.  You  can  change  this  behaviour  by  editing  Makefile or running
                     ./configure --datadir=...

              index string
                     Specifies the filename for the index file.  Path matter is similar  to  that
                     described above in "data" option .

              index_suffix string
                     This  is optional index file to make 'suffix' search strategy faster (binary
                     search).     It    is    generated    by     'dictfmt_index2suffix'.     Run
                     "dictfmt_index2suffix  --help" for more information.  Path matter is similar
                     to that described above in "data" option .

              index_word string
                     This is optional index file to make 'word' search  strategy  faster  (binary
                     search).   It  is generated by 'dictfmt_index2word'. Run "dictfmt_index2word
                     --help" for more information.  Path matter  is  similar  to  that  described
                     above in "data" option .

              prefilter string
                     Specifies  the  prefilter command.  When  a chunk of the compressed database
                     is  read, it will be filtered  with  this filter before being  decompressed.
                     This  may be  used to provide  some additional compression  that knows about
                     the data and can provide better compression than the LZ77 algorithm used  by
                     zlib.

              postfilter string
                     Specifies  the  postfilter command.  When a chunk of the compressed database
                     is read, it will be filtered with this filter before the offset  and  length
                     for  the  entry are used to access data.  This is provided for symmetry with
                     the prefilter command, and may  also  be  useful  for  providing  additional
                     database compression.

              filter string
                     Specifies  the  filter  command.   After  the  entry  is  extracted from the
                     database, it will be filtered with this filter.  This may be used to provide
                     formatting for the entry (e.g., for html).

              name string
                     Specifies  the  short name of the database (e.g., "1913 Webster's").  If the
                     string begins with @, then it specifies the  headword  to  look  up  in  the
                     dictionary  to  find  the  short  name  of  the  database.   The  default is
                     "@00-database-short", but this may be changed in the defs.h file at  compile
                     time (DICT_SHORT_ENTRY_NAME).

              info string
                     Specifies the information about database.  If the string begins with @, then
                     it specifies the headword to look up in the dictionary to find  information.
                     The  default  is  "@00-database-info", but this may be changed in the defs.h
                     file at compile time (DICT_INFO_ENTRY_NAME).

              invisible
                     Makes dictionary invisible to the clients i.e. this dictionary will  not  be
                     recognized  or  shown  by  DEFINE, MATCH, SHOW INFO, SHOW SERVER and SHOW DB
                     commands. If some definitions or matches are found in invisible  dictionary,
                     the  name of the upper visible virtual dictionary is returned.  Dictionaries
                     '*' and '!' don't include invisible ones.  NOTE: Invisible dictionaries  are
                     completely  inaccessible  (and  invisible)  to  the  client  unless they are
                     included  to  the  virtual  or  MIME  dictionary  (See  database_virtual  or
                     database_mime database sections).

              disable_strategy string
                     Disables  the  specified strategy for database.  This may be useful for slow
                     dictionaries (plugins) or for dictionaries included to virtual ones.  For an
                     example see file examples/dictd_complex.conf.

              default_strategy string
                     Specifies  the strategy which will be used if the database is accessed using
                     the strategy '.'.  I.e. this directive is  the  way  to  set  the  preferred
                     search  strategy  per  database.  For example, instead of strategy lev , the
                     strategy word may be preferred for databases mainly containing the multiword
                     phrases but the single words.

       Virtual Database Specification
              The virtual database specification describes the virtual database:

              database_list string
                     Specifies  a list of databases which are included into the virtual database.
                     Database names are in the string and are separated by comma.

              name string
                     Specifies the short name of the database. See database specification

              info string
                     Specifies the information about database. See database specification

              invisible
                     Makes dictionary invisible to the clients. See database specification

              disable_strategy string
                     Disables the specified strategy for database.  See database specification

       Plugin Specification

              plugin string
                     Specifies a filename of the plugin.

              data string
                     Specifies data for initializing plugin.

              name string
                     Specifies the short name of the database.  See  Database  Specification  for
                     more information.

              info string
                     Specifies  the  information  about database.  See Database Specification for
                     more information.

              invisible
                     Makes dictionary invisible to the clients.  See Database  Specification  for
                     more information.

              disable_strategy string
                     Disables  the  specified  strategy for database.  See Database Specification
                     for more information.

              default_strategy string
                     Sets the default search strategy for database.  See  Database  Specification
                     for more information.

       Mime Specification

              dbname_nomime string
                     Specifies  the  real database name which is used in case OPTION MIME command
                     was NOT received from a client.

              dbname_mime string
                     Specifies the real database name which is used in case OPTION  MIME  command
                     WAS received from a client.  A necessary MIME header is set while creating a
                     database.  See dictfmt(1) for option --mime-header.

              name string
                     Specifies the short name of the database.  See  Database  Specification  for
                     more information.

              info string
                     Specifies  the  information  about database.  See Database Specification for
                     more information.

              invisible
                     Makes dictionary invisible to the clients.  See Database  Specification  for
                     more information.

              disable_strategy string
                     Disables  the  specified  strategy for database.  See Database Specification
                     for more information.

              default_strategy string
                     Sets the default search strategy for database.  See  Database  Specification
                     for more information.

       include string
              The text of the file "string" (usually a database specification) will be read as if
              it appeared at this location in the configuration file.  Nested  includes  are  not
              permitted.

DETERMINATION OF ACCESS LEVEL

       When  a  client  connects,  the  global access specification is scanned, in order, until a
       specification matches.  If no access specification exists, all access  is  allowed  (e.g.,
       the  action is the same as if "allow *" was the only item in the specification).  For each
       item, both the hostname and IP are checked. For example,  consider  the  following  access
       specification:
              allow 10.42.*
              authonly *.edu
              deny *
       With  this  specification,  all  clients  in  the  10.42 network will be allowed access to
       unrestricted databases; all clients from *.edu sites will be allowed to authenticate,  but
       will  be  denied access to all databases, even those which are otherwise unrestricted; and
       all other clients will have their connection terminated immediately.   The  10.42  network
       clients  can  send  an  AUTH  command  and gain access to restricted databases.  The *.edu
       clients must send an  AUTH  command  to  gain  access  to  any  databases,  restricted  or
       unrestricted.

       When  the  AUTH  command  is sent, the access list for each database is scanned, in order,
       just as the global access list is scanned.  However, after authentication, the client  has
       an associated username.  For example, consider the following access specification:
              user u1
              deny *.com
              user u2
              allow *
       If the client authenticated as u1, then the client will have access to this database, even
       if the client comes from a *.com site.  In contrast, if the client  authenticated  as  u2,
       the client will only have access if it does not come from a *.com site.  In this case, the
       "user u2" is redundant, since that client would also match "allow *".

       Warning: Checks are performed for domain names and for IP addresses.  However, if  reverse
       DNS  for  a  specific  site  is  not working, it is possible that a domain name may not be
       available for checking.  Make sure that all denials use IP  addresses.   (And  consider  a
       future  enhancement:  if  a  domain name is not available, should denials that depend on a
       domain name match anything?  This is the  more  conservative  viewpoint,  but  it  is  not
       currently implemented.)

SEARCH ALGORITHMS

       The  DICT standard specifies a few search algorithms that must be implemented, and permits
       others to be supported on a server-dependent basis.  The following search  strategies  are
       supported  by  this  server.   Note that all strategies are case insensitive.  Most ignore
       non-alphanumeric, non-whitespace characters.

       exact  An exact match.  This algorithm uses a binary search and  is  one  of  the  fastest
              search algorithms available.

       lev    The  Levenshtein  algorithm (string edit distance of one).  This algorithm searches
              for all words which are within an edit distance of one from the  target  word.   An
              "edit"  means  an insertion, deletion, or transposition.  This is a rapid algorithm
              for correcting spelling errors, since many spelling errors are within a Levenshtein
              distance of one from the original word.

       prefix Prefix match.  This algorithm also uses a binary search and is very fast.

       nprefix
              Like  prefix  but  returns the specified range of matches. For example, when prefix
              strategy returns 1000 matches, you can get only 100 ones  skipping  the  first  800
              matches.  This is made by specified these limits in a query like this: 800#100#app,
              where 800 is skip count, 100 is a number of matches you want to get  and  "app"  is
              your  query.   This  strategy  allows  one  to  implement  DICT  client  with  fast
              autocompletion (although it is not trivial) just like  many  standalone  dictionary
              programs do.

              NOTE:  If you access the dictionary "*" (or virtual one) with nprefix strategy, the
              same range is set for each database in it, but globally for all  matches  found  in
              all databases.

              NOTE:  In  case  you access non-english dictionary the returned matches may be (and
              mostly will be) NOT ordered in alphabetic order.

       re     POSIX 1003.2 (modern) regular expression search.  Modern  regular  expressions  are
              the  ones  used  by egrep(1).  These regular expressions allow predefined character
              classes (e.g., [[:alnum:]], [[:alpha:]], [[:digit:]], and [[:xdigit:]]  are  useful
              for this application); uses * to match a sequence 0 or more matches of the previous
              atom; uses + to match a sequence of 1 or more matches of the previous atom; uses  ?
              to  match  a  sequence  of 0 or 1 matches of the previous atom; used ^ to match the
              beginning of a word, uses $  to  match  the  end  of  a  word,  and  allows  nested
              subexpression  and alternation with () and |.  For example, "(foo|bar)" matches all
              words that contain either "foo" or "bar".  To match these special characters,  they
              must  be  quoted  with  two  backslashes (due to the quoting characteristics of the
              server).  Warning: Regular expression matches can take 10 to 300 times longer  than
              substring  matches.   On a busy server, with many databases, this can required more
              than 5 minutes of  waiting  time,  depending  on  the  complexity  of  the  regular
              expression.

       regexp Old  (basic) regular expressions.  These regular expressions don't support |, +, or
              ?.  Groups use escaped parentheses.  While modern regular expressions are generally
              easier  to  use, basic regular expressions have a back reference feature.  This can
              be used to match a second occurrence of something that was  already  matched.   For
              example,  the following expression finds all words that begin and end with the same
              three letters:
                  ^\\(...\\).*\\1$

              Note the use of the double backslashes to escape the special characters.   This  is
              required  by  the DICT protocol string specification (a single backslash quotes the
              next character -- we use two to get a  single  backslash  through  to  the  regular
              expression engine).  Warning: Note that the use of backtracking is even slower than
              the use of general regular expressions.

       soundex
              The Soundex algorithm, a classic algorithm for finding words that sound similar  to
              each other.  The algorithm encodes each word using the first letter of the word and
              up to three digits.  Since the first letter is known,  this  search  is  relatively
              fast,  and  it  sometimes  good for correcting spelling errors when the Levenshtein
              algorithm doesn't help.

       substring
              Match a substring anywhere in the headword.  This search strategy uses  a  modified
              Boyer-Moore-Horspool  algorithm.   Since it must search the whole index file, it is
              not as fast as the exact and prefix matches.

       suffix Suffix match.  This search  strategy  also  uses  a  modified  Boyer-Moore-Horspool
              algorithm,  and  is  as fast as the substring search.  If the optional index_suffix
              string file is listed in the configuration file this search is much faster.

       word   Match any single word, even if  part  of  a  multi-word  entry.   If  the  optional
              index_word  string  file  is  listed in the configuration file this search strategy
              works much faster.

       first  Match the first word that begins a multi-word entry.

       last   Match the last word that ends a multi-word entry.   If  the  optional  index_suffix
              string  file  is  listed  in the configuration file this search strategy works much
              faster.

DATABASE FORMAT

       Databases for dictd are distributed separately.  A database consists of two files.  One is
       a flat text file, the other is the index.

       The flat text file contains dictionary entries (or any other suitable data), and the index
       contains tab-delimited tuples consisting of the headword, the byte offset  at  which  this
       entry  begins in the flat text file, and the length of the entry in bytes.  The offset and
       length are encoded using base 64 encoding using the 64-character subset  of  International
       Alphabet  IA5  discussed  in  RFC  1421  (printable  encoding) and RFC 1522 (base64 MIME).
       Encoding the offsets in base 64 saves considerable space when compared with the usual base
       10  encoding,  while  still  permitting tab characters (ASCII 9) to be used for delimiting
       fields in a record.  Each record ends with a newline (ASCII 10),  so  the  index  file  is
       human readable.

       Some headwords are used by dictd especially

       00-database-info  Contains  the  information about database which is returned by SHOW INFO
       command, unless it is specified in the configuration file.

       00-database-short Contains the short name of the database which is  returned  by  SHOW  DB
       command, unless it is specified in the configuration file.  See dictfmt -s.

       00-database-url URL where original dictionary sources were obtained from.  See dictfmt -u.
       This headword is not used by dictd

       00-database-utf8 Presents if dictionary is encoded using UTF-8.  See dictfmt --utf8

       00-database-8bit-new Presents if dictionary is encoded  using  8-BIT  character  set  (not
       ASCII and not UTF8).  See dictfmt --locale.

       The flat text file may be compressed using gzip(1) (not recommended) or dictzip(1) (highly
       recommended).  Optimal speed will be obtained using an uncompressed  file.   However,  the
       gzip  compression algorithm works very well on plain text, and can result in space savings
       typically between 60 and 80%.  Using a file compressed with gzip(1)  is  not  recommended,
       however,  because  random  access  on  the  file  can  only  be  accomplished  by serially
       decompressing the whole file, a process which is prohibitively slow.  dictzip(1) uses  the
       same  compression algorithm and file format as does gzip(1), but provides a table that can
       be used to randomly access compressed blocks in the file.  The use of 50-64kB  blocks  for
       compression  typically degrades compression by less than 10%, while maintaining acceptable
       random access capabilities for  all  data  in  the  file.   As  an  added  benefit,  files
       compressed   with  dictzip(1)  can  be  decompressed  with  gzip(1)  or  zcat(1).   (Note:
       recompressing a dictzip'd file using, for example, znew(1) will destroy the random  access
       characteristics of the file.  Always compress data files using dictzip(1).)

SIGNALS

       SIGHUP causes dictd to reread configuration file and reinitialize databases.

       SIGUSR1  causes dictd to unload databases. Then dictd returns 420 status (instead of 220).
       To load databases again, send SIGHUP signal. Because database files are mmap'ed(2) , it is
       impossible  to  update  them  while  dictd is running.  So, if you need to update database
       files and reread configuration file,  first,  send  SIGUSR1  signal  to  dictd  to  unload
       databases, update files, and then send SUGHUP signal to load them again.

COPYING

       The  main  source  files  for  the  dictd  server and the dictzip compression program were
       written by Rik Faith (faith@dict.org) and are distributed  under  the  terms  of  the  GNU
       General Public License.  If you need to distribute under other terms, write to the author.

       The  main  libraries  used  by  these programs (zlib, regex, libmaa) are distributed under
       different terms, so you may be able to  use  the  libraries  for  applications  which  are
       incompatible with the GPL -- please see the copyright notices and license information that
       come with the libraries for more information, and consult with your  attorney  to  resolve
       these issues.

BUGS

       The  regular expression searches do not ignore non-whitespace, non-alphanumeric characters
       as do the other searches.  In practice, this isn't much of a problem.

WARNINGS

       Conformance of regular expressions (used by 're' and 'regexp' search  strategies)  to  ERE
       and  BRE  depends  on  library  you build dictd with.  Whether 're' and 'regex' strategies
       support utf8 depends on library you build dictd with.

FILES

       /etc/dictd/dictd.conf
              dictd configuration file

       /usr/sbin/dictd
              dictd daemon itself

       /var/run/dictd.pid
              File for storing pid of dictd daemon

       /usr/share/dictd
              The default directory for dictd databases (.index and .dict[.dz] files)

SEE ALSO

       examples/dictd*.conf, dictfmt(1), dict(1), dictzip(1), gunzip(1), zcat(1), webster(1), RFC
       2229

                                          29 March 2002                                  DICTD(8)