# makeuserdb

## Name

make -- create /etc/userdb

## Synopsis

makeuserdb

pw2userdb

vchkpw2userdb [--vpopmailhome=dir] [--todir=dir]

## DESCRIPTION

makeuserdb creates `/etc/userdb.dat` from the contents of `/etc/userdb`. `/etc/userdb`'s contents are described later in this document. `Maildrop`, `Courier`, and other applications use `/etc/userdb.dat` as a substitute/complement for your system password file. The usual purpose for `/etc/userdb.dat` is to specify "virtual" accounts - accounts that do not have an associated system login. Usually (but not necessarily) all virtual accounts share the same system userid. `/etc/userdb.dat` may also replace your system password file. Because the system password file is a text file, when there's a large number of accounts it will be significantly faster to search `@userdb.dat@`, which is a binary database, instead of a flat text file that the system password file usually is.

The makeuserdb command can be safely executed during normal system activity.

### Format of `/etc/userdb`

`/etc/userdb` is a plain text file that can be created using any text editor. Blank lines are ignored. Lines that start with the # character are comments, and are also ignored. Other lines define properties of a single "account", one line per account. `/etc/userdb` may be a directory instead of a plain file. In that case all files in `/etc/userdb` are essentially concatenated, and are treated as a single file. Each line takes the following format:

> name<TAB>field=value|field=value...

name is the account name. name MUST contain only lowercase characters If `Courier` is configured to treat lowercase and uppercase account names as identical, name is followed by exactly one tab character, then a list of field/value pairs separated by vertical slashes. field is the name of the field, value is the field value. Fields and values themself cannot contain slashes or control characters. Fields may be specified in any order. Here are all the currently defined fields. Note that not every field is used by every application that reads `/etc/userdb.dat`.

> `uid` - value is a (possibly) unique numerical user ID for this account.

> `gid` - value is a (possibly) unique numerical group ID for this account.

> `home` - value is the account's home directory.

> `shell` - value is the account's default login shell.

> `systempw` - value is the account's password. See userdbpw(8) for details on how to set up this field.

> `pop3pw, esmtppw, imappw...` - value specifies a separate password used only for authenticating access using a specific service, such as POP3, IMAP, or anything else. If not defined, `systempw` is always used. This allows access to an account to be restricted only to certain services, such as POP3, even if other services are also enabled on the server.

> `mail` - value specifies the location of the account's Maildir mailbox. This is an optional field that is normally used when userdb is used to provide aliases for other mail accounts. For example, one particular multi-domain E-mail service configuration that's used by both `Qmail` and `Courier` servers is to deliver mail for a mailbox in a virtual domain, such as "user@example.com", to a local mailbox called "example-user". Instead of requiring the E-mail account holder to log in as "example-user" to download mail from this account, a userdb entry for "user@example.com" is set up with `mail` set to the location of example-user's Maildir mailbox, thus hiding the internal mail configuration from the E-mail account holder's view.

> `quota` - value specifies the maildir quota for the account's Maildir. This has nothing to do with actual filesystem quotas. `Courier` has a software-based Maildir quota enforcement mechanism which requires additional setup and configuration. See maildirquota(7) for additional information.

### `/etc/userdbshadow.dat`

All fields whose name ends with 'pw' will NOT copied to `/etc/userdb.dat`. These fields will be copied to `/etc/userdbshadow.dat`. makeuserdb creates `/etc/userdbshadow.dat` without any group and world permissions. Note that makeuserdb reports an error if /etc/userdb has any group or world permissions.

### CONVERTING `/etc/passwd` and vpopmail to `/etc/userdb` format

pw2userdb reads the `/etc/passwd` and `/etc/shadow` files and converts all entries to the `/etc/userdb` format, printing the result on standard output. The output of pw2userdb can be saved as /etc/userdb (or as some file in this subdirectory). Linear searches of `/etc/passwd` can be very slow when you have tens of thousands of accounts. Programs like maildrop always look in `/etc/userdb` first. By saving the system password file in `/etc/userdb` it is possible to significantly reduce the amount of time it takes to look up this information.

After saving the output of pw2userdb, you must still run makeuserdb to create `/etc/userdb.dat`.

vchkpw2userdb converts a vpopmail-style directory hierarchy to the `/etc/userdb` format. This is an external virtual domain management package that's often used with `Qmail` servers.

Generally, an account named 'vpopmail' is reserved for this purpose. In that account the file `users/vpasswd` has the same layout as `/etc/passwd`, and performs a similar function, except that all userid in `users/vpasswd` have the same userid. Additionally, the `domains` subdirectory stores virtual accounts for multiple domains. For example, `domains/example.com/vpasswd` has the passwd file for the domain `example.com`. Some systems also have a soft link, `domains/default`, that points to a domain that's considered a "default" domain.

The vchkpw2userdb reads all this information, and tries to convert it into the `/etc/userdb` format. The `--vpopmailhost` option specifies the top level directory, if it is not the home directory of the vpopmail account.

The vchkpw2userdb script prints the results on standard output. If specified, the `--todir` option tries to convert all `vpasswd` files one at a time, saving each one individually in dir. For example:

> mkdir /etc/userdb
> vchkpw2userdb --todir=/etc/userdb/vpopmail
> makeuserdb

It is still necessary to run makeuserdb, of course, to create the binary database file `/etc/userdb.dat`

NOTE: You are still required to create the /etc/userdb entry which maps system userids back to accounts, "uid=<TAB>name", if that's applicable. vchkpw2userdb will not do it for you.

NOTE: makeuserdb may complain about duplicate entries, if your "default" entries in `users/vpasswd` or `domains/default/vpasswd` are the same as anything in any other `/etc/userdb` file. It is also likely that you'll end up with duplicate, but distinct, entries for every account in the default domain. For example, if your default domain is example.com, you'll end up with duplicate entries - you'll have entries for both `user` and `user@example.com`.

If you intend to maintain the master set of accounts using vchkpw/vpopmail, in order to avoid cleaning this up every time, you might want to consider doing the following: run vchkpw2userdb once, using the `--todir` option. Then, go into the resulting directory, and replace one of the redundant files with a soft link to `/dev/null`. This allows you to run vchkpw2userdb without having to go in and cleaning up again, afterwards.

## FILES

`/etc/userdb`
`/etc/userdb.dat`
`/etc/userdbshadow.dat`
`/etc/userdb.tmp` - temporary file
`/etc/userdbshadow.tmp` - temporary file

## BUGS

makeuserdb is a Perl script, and uses Perl's portable locking. Perl's documentation notes that certain combinations of locking options may not work with some networks.

## SEE ALSO

userdb(8), maildrop(8), courier(8), maildirquota(7).