dbmmanage - Create and update user authentication files in
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 dbmmanage. 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 necessary to configure user
authentication in httpd see the Apache manual, which is
part of the Apache distribution or can be found at
The filename of the DBM format file. Usually without
the extension .db, .pag, or .dir.
This selects the operation to perform:
add Adds an entry for username to filename using
the encrypted password encpassword.
adduser Asks for a password and then adds an entry for
username to filename .
check Asks for a password and then checks if user-
name is in filename and if its 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
password already has to be crypted.
update Same as the "adduser" command, except that it
makes sure username already exists in file-
view Just displays the complete contents of the DBM
username The user for which the update operation is
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. Unfortunately, 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, dbmmanage
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
ordering. Similar care must be taken if using programs
in other languages, like C, to access these files.
Apache's mod_auth_db.c module corresponds to the Berkeley
DB 2 library, while 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
March 1998 2 [ Back ]