Provided by: dictd_1.12.1+dfsg-3_i386 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 address
              Overrides the keyword listen_to 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 string
                     Binds  socket  to  the specified address.  If you want to
                     allow connections to dict  server  from  localhost  only,
                     apply
                     listen_to 127.0.0.1

              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)