mandb - create or update the manual page index caches


   mandb [-dqsucpt?V] [-C file] [manpath]
   mandb [-dqsut] [-C file] -f filename ...


   mandb  is  used  to initialise or manually update index database caches
   that are usually maintained by man.   The  caches  contain  information
   relevant  to  the  current  state  of  the  manual  page system and the
   information stored within them is  used  by  the  man-db  utilities  to
   enhance their speed and functionality.

   When  creating  or  updating  an index, mandb will warn of bad ROFF .so
   requests, bogus manual page filenames and manual pages from  which  the
   whatis cannot be parsed.

   Supplying mandb with an optional colon-delimited path will override the
   internal system manual page  hierarchy  search  path,  determined  from
   information found within the man-db configuration file.


   mandb  can  be  compiled  with  support  for  any  one of the following
   database types.

   Name          Type                   Async   Filename
   Berkeley db   Binary tree            Yes
   GNU gdbm      Hashed                 Yes     index.db
   UNIX ndbm     Hashed                 No      index.(dir|pag)

   Those database types that support asynchronous updates provide enhanced
   speed  at  the  cost  of  possible  corruption  in the event of unusual
   termination.  In an unusual case where this has  occurred,  it  may  be
   necessary  to rerun mandb with the -c option to re-create the databases
   from scratch.


   -d, --debug
          Print debugging information.

   -q, --quiet
          Produce no warnings.

   -s, --no-straycats
          Do not spend time looking  for  or  adding  information  to  the
          databases regarding stray cats.

   -p, --no-purge
          Do  not spend time checking for deleted manual pages and purging
          them from the databases.

   -c, --create
          By default, mandb will try  to  update  any  previously  created
          databases.   If  a  database  does not exist, it will create it.
          This option forces mandb to delete previous  databases  and  re-
          create  them  from scratch, and implies --no-purge.  This may be
          necessary if a database becomes corrupt or  if  a  new  database
          storage scheme is introduced in the future.

   -u, --user-db
          Create   user   databases  only,  even  with  write  permissions
          necessary to create system databases.

   -t, --test
          Perform correctness checks on  manual  pages  in  the  hierarchy
          search  path.   With  this option, mandb will not alter existing

   -f, --filename
          Update only the entries for the given filename.  This option  is
          not  for  general  use; it is used internally by man when it has
          been compiled with the MAN_DB_UPDATES option and  finds  that  a
          page is out of date.  It implies -p and disables -c and -s.

   -C file, --config-file=file
          Use  this  user  configuration  file  rather than the default of

   -?, --help
          Show the usage message, then exit.

          Print a short usage message and exit.

   -V, --version
          Show the version, then exit.


   0      Successful program execution.

   1      Usage, syntax, or configuration file error.

   2      Operational error.

   3      A child process failed.


   The following warning messages can be emitted during database building.

   <filename>: whatis parse for page(sec) failed
          An attempt to extract whatis line(s) from the  given  <filename>
          failed.   This  is  usually due to a poorly written manual page,
          but if many such messages are emitted  it  is  likely  that  the
          system contains non-standard manual pages which are incompatible
          with the man-db whatis parser.  See the WHATIS  PARSING  section
          in lexgrog(1) for more information.

   <filename>: is a dangling symlink
          <filename>  does not exist but is referenced by a symbolic link.
          Further  diagnostics  are  usually  emitted  to   identify   the
          <filename> of the offending link.

   <filename>: bad symlink or ROFF `.so' request
          <filename>  is  either  a  symbolic  link to, or contains a ROFF
          include request to, a non existent file.

   <filename>: ignoring bogus filename
          The <filename> may or may not be a valid  manual  page  but  its
          name  is  invalid.   This  is  usually due to a manual page with
          sectional extension <x> being put in manual page section <y>.

   <filename_mask>: competing extensions
          The wildcard <filename_mask> is not  unique.   This  is  usually
          caused  by  the  existence of both a compressed and uncompressed
          version of the same manual page.  All but the  most  recent  are


          man-db configuration file.

          An FHS compliant global index database cache.

   Older locations for the database cache included:

          A traditional global index database cache.

          An alternate or FSSTND compliant global index database cache.


   lexgrog(1), man(1), manpath(5), catman(8)

   The  WHATIS PARSING section formerly in this manual page is now part of


   Wilf. (
   Fabrizio Polacco (
   Colin Watson (


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.