MANDB(8) Manual pager utils MANDB(8)
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 man-
ual 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 re-
quests, 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 in-
formation 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 termi-
nation. 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 data-
bases 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 data-
bases. 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page is out of date.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 lex-
grog(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 <file-
name> of the offending link.
<filename>: bad symlink or ROFF `.so' request
<filename> is either a symbolic link to, or contains a ROFF in-
clude 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 ig-
nored.
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
2.13.1 2025-05-02 MANDB(8)
Generated by dwww version 1.16 on Tue Dec 16 04:41:39 CET 2025.