NAME

       mandb - create or update the manual page index caches

SYNOPSIS

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

DESCRIPTION

       mandb  is used to initialise or manually update index database caches.  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.

DATABASE CACHES

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

       Name          Async   Filename
       ──────────────────────────────────────
       Berkeley db   Yes     index.bt
       GNU gdbm      Yes     index.db
       UNIX ndbm     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.

OPTIONS

       -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 databases.

       -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 ~/.manpath.

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

       --usage
              Print a short usage message and exit.

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

EXIT STATUS

       0      Successful program execution.

       1      Usage, syntax, or configuration file error.

       2      Operational error.

       3      A child process failed.

DIAGNOSTICS

       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 ignored.

FILES

       /etc/manpath.config
              man-db configuration file.

       /var/cache/man/index.(bt|db|dir|pag)
              An FHS compliant global index database cache.

       Older locations for the database cache included:

       /usr/man/index.(bt|db|dir|pag)
              A traditional global index database cache.

       /var/catman/index.(bt|db|dir|pag)
              An alternate or FSSTND compliant global index database cache.

SEE ALSO

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

       The WHATIS PARSING section formerly in this manual page is now part of lexgrog(1).

AUTHOR

       Wilf. (G.Wilford@ee.surrey.ac.uk).
       Fabrizio Polacco (fpolacco@debian.org).
       Colin Watson (cjwatson@debian.org).

BUGS

       https://gitlab.com/man-db/man-db/-/issues
       https://savannah.nongnu.org/bugs/?group=man-db