dbmmanage - Create and update user authentication files in DBM format
dbmmanage filename [ command ] [ username [ encpasswd ] ]
dbmmanage is used to create and update the DBM format files used to store usernames and
password for basic authentication of HTTP users. Resources available from the httpd
Apache web server can be restricted to just the users listed in the files created by dbm-
manage. This program can only be used when the usernames are stored in a DBM file. To use
a flat-file database see htpasswd.
This manual page only lists the command line arguments. For details of the directives nec-
essary to configure user authentication in httpd see the Apache manual, which is part of
the Apache distribution or can be found at http://www.apache.org/.
The filename of the DBM format file. Usually without the extension .db, .pag, or
This selects the operation to perform:
add Adds an entry for username to filename using the encrypted password encpass-
adduser Asks for a password and then adds an entry for username to filename .
check Asks for a password and then checks if username is in filename and if it's
password matches the specified one.
delete Deletes the username entry from filename.
import Reads username:password entries (one per line) from STDIN and adds them to
filename. The passwords already has to be crypted.
update Same as the "adduser" command, except that it makes sure username already
exists in filename.
view Just displays the complete contents of the DBM file.
username The user for which the update operation is performed.
One should be aware that there are a number of different DBM file formats in existence,
and with all likelihood, libraries for more than one format may exist on your system. The
three primary examples are NDBM, the GNU project's GDBM, and Berkeley DB 2. Unfortu-
nately, all these libraries use different file formats, and you must make sure that the
file format used by filename is the same format that dbmmanage expects to see. dbmmanage
currently has no way of determining what type of DBM file it is looking at. If used
against the wrong format, will simply return nothing, or may create a different DBM file
with a different name, or at worst, it may corrupt the DBM file if you were attempting to
write to it.
dbmmanage has a list of DBM format preferences, defined by the @AnyDBM::ISA array near the
beginning of the program. Since we prefer the Berkeley DB 2 file format, the order in
which dbmmanage will look for system libraries is Berkeley DB 2, then NDBM, and then GDBM.
The first library found will be the library dbmmanage will attempt to use for all DBM file
transactions. This ordering is slightly different than the standard @AnyDBM::ISA ordering
in perl, as well as the ordering used by the simple dbmopen() call in Perl, so if you use
any other utilities to manage your DBM files, they must also follow this preference order-
ing. Similar care must be taken if using programs in other languages, like C, to access
Apache's mod_auth_dbm.c corresponds to the NDBM library. Also, one can usually use the
file program supplied with most Unix systems to see what format a DBM file is in.
March 1998 dbmmanage(1)