---
name: "userdb"
section: "8"
platform: "linux"
package: "courier-authlib-userdb"
version: "0.72.4-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/userdb"
---

# userdb(8)

manipulate /etc/courier/userdb

## NAME

userdb - manipulate /etc/courier/userdb

## SYNOPSIS

**userdb** {*addr*} set {*field*=*value*...}

**userdb** {*addr*} unset {*field*...}

**userdb** {*addr*} del

**userdb** {*path/addr*} \[set \| unset \| del\] ...

**userdb** -f {*file*} {*adr*} \[set \| unset \| del\] ...

**userdb** -show {*path*}

**userdb** -show {*path*} {*addr*}

**userdb** -show -f {*file*}

**userdb** -show -f {*file*} {*addr*}

## DESCRIPTION

**userdb** is a convenient script to individually manipulate entries in /etc/courier/userdb. See [**makeuserdb**(8)](/makeuserdb/8.md)\[1\] for a description of its contents. /etc/courier/userdb can always be edited using any text editor, but **userdb** is a convenient way to modify this file from another script.

/etc/courier/userdb can also be a subdirectory, instead of a file. Specify *foo/bar/addr* to manipulate *addr* in the file /etc/courier/userdb*/foo/bar*. You can also use the **-f** flag: **-f** */etc/courier/userdb/foo/bar* is equivalent. Use whatever form makes the most sense to you.

/etc/courier/userdb must not have any group or world permissions. That's because its contents may include system passwords (depending upon the application which uses this virtual user account database).

Each line in /etc/courier/userdb takes following form:

*addr*\<TAB\>*field*=*value*\|*field*=*value*...

*addr* specifies a unique virtual address. It is followed by a single tab character, then a list of *field*=*value* pairs, separated by vertical slash characters. See [**makeuserdb**(8)](/makeuserdb/8.md)\[1\] for field definitions.

A text editor can be used to add blank lines or comments in /etc/courier/userdb. Any blank lines or comments are ignored by the **userdb** script.

The names of the actual fields, and their contents, are defined entirely by applications that use the /etc/courier/userdb database, the **userdb** command just adds or removes arbitrary fields.

For example:

```
userdb default/info set mail=/home/mail/info
```

This command accesses the address "info" in /etc/courier/userdb/default.

If the second argument to **userdb** is "*set*", the remaining arguments are taken as *field=value* pairs, which are added to the record for *addr*. If there is no record for *addr*, a new record will be appended to the file. If *addr* exists, any existing values of any specified fields are removed. If *=value* is missing, **userdb** stops and prompts for it. This is useful if you're setting a password field, where you do not want to specify the password on the command line, which can be seen by the [**ps**(1)](/ps/1.md) command. If **userdb** is being executed by a script, the value can be provided on standard input.

Use "*unset*" to delete fields from an existing record. Use "*del*" to delete all fields in the existing record, plus the record itself.

### DISPLAYING /etc/courier/userdb

If the first argument to userdb is *-show*, **userdb** displays the contents of /etc/courier/userdb. If /etc/courier/userdb is a subdirectory, *path* must refer to a specific file in /etc/courier/userdb. The *-f* option can be used instead of *path* in order to specify an arbitrary file.

If *addr* is not specified, **userdb** produces a list, on standard output, containing all addresses found in the file, on per line. If *addr* is specified, **userdb** produces a list, on standard output, of all the fields in /etc/courier/userdb for this *addr*.

### International domains

*addr*s with international domains should use UTF-8 to specify an international domain name:

```
userdb postmaster@test.испытание set \
        home=/home/postmaster.test.com uid=999 gid=999
```

### REBUILDING /etc/courier/userdb.dat

The actual virtual account/address database is /etc/courier/userdb.dat. This is a binary database file. **/etc/courier/userdb** is the plain text version. After running **userdb**, execute the [**makeuserdb**(8)](/makeuserdb/8.md)\[1\] command to rebuild /etc/courier/userdb.dat for the changes to take effect.

## BUGS

*addr* must be unique. If /etc/courier/userdb is a subdirectory, it's possible to create the same *addr* in different files in the subdirectory. This is an error that is not currently detected by **userdb**, however the subsequent [**makeuserdb**(8)](/makeuserdb/8.md)\[1\] command will fail with an error message.

## FILES

/etc/courier/userdb - plain text file, or directory of plain text files

.lock.filename - lock file for filename

.tmp.filename - temporary file used to create new contents of filename

## SEE ALSO

[**makeuserdb**(8)](/makeuserdb/8.md)\[1\], [**userdbpw**(8)](/userdbpw/8.md)\[2\]

## NOTES

- 1\.

  [**makeuserdb**(8)](/makeuserdb/8.md)

  \[set $man.base.url.for.relative.links\]/makeuserdb.html

- 2\.

  [**userdbpw**(8)](/userdbpw/8.md)

  \[set $man.base.url.for.relative.links\]/userdbpw.html