userdb(4)userdb(4)NAME
userdb - user database for per-user information
SYNOPSISDESCRIPTION
The user database is used for storing per-user information. It con‐
sists of the directory and the files within it. Each file name is a
two-digit hexadecimal number from to The directory and files are cre‐
ated either at installation time or by the command.
The per-user information resides in user entries in the database, and
consists of any number of pairs, which are used to define the behavior
of configurable features. A per-user value in overrides any corre‐
sponding system-wide default configured in the file, as described in
security(4).
The file indicates which attributes can be configured with a per-user
value in This list includes the following attributes which are
described in security(4):
Allow or do not allow null passwords.
Audit or do not audit users.
Maximum number of authentication failures allowed.
Display or do not display last login information.
Restrict login time periods.
Minimum password length.
Number of simultaneous logins allowed per user.
Override reading system default password aging
values from the file during a password change.
Password history depth.
Minimum number of lower case characters allowed in a password.
Minimum number of upper case characters allowed in a password.
Minimum number of digit characters allowed in a password.
Minimum number of special characters allowed in a password.
Define umask for file creation.
Notes
When defining attributes, first configure default values in as
described in security(4), and then configure per-user exceptions in the
user database,
In addition to the configurable attributes, there are internal
attributes that are not user configurable and are normally modified
only by programs that enforce system security. The file indicates
which attributes are configurable and which are internal.
Use the command to verify or fix information in the user database,
To disable the user database, create a file called This causes all
database reads and writes to return an error code indicating that the
database is disabled and should be ignored. Note that, if the user
database is disabled for a long period and then re-enabled, it will
contain stale data. This can cause unwanted side effects.
WARNINGS
Use the command to modify information in Do not use a text editor,
because the database contains checksums and other binary data, and edi‐
tors do not follow the file locking conventions that are used to con‐
trol access to the database.
NFS mounting this database is not supported.
FILES
user database
security defaults configuration file
security attributes description file
SEE ALSOuserdbck(1M), userdbget(1M), userdbset(1M), userdb_read(3), secu‐
rity(4).
userdb(4)
