---
name: "makemap"
section: "8"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd", "openbsd"]
url: "https://new.carta.tech/makemap"
---

# makemap(8)

create database maps for sendmail

## NAME

makemap - create database maps for sendmail

## SYNOPSIS

**makemap** \[**-C** *file*\] \[**-N**\] \[**-c** *cachesize*\] \[**-d**\] \[**-D** *commentchar*\] \[**-e**\] \[**-f**\] \[**-i** *type*\] \[**-l**\] \[**-o**\] \[**-r**\] \[**-s**\] \[**-t** *delim*\] \[**-u**\] \[**-v**\] *maptype mapnam*

## DESCRIPTION

**Makemap** creates the database maps used by the keyed map lookups in [sendmail(8)](/sendmail/8.md).   It reads input from the standard input and outputs them to the indicated *mapname.*

Depending on how it is compiled, **makemap** handles different database formats,  selected using the *maptype* parameter.   They may be

- dbm

  DBM format maps.   This requires the  ndbm(3)  library.

- btree

  B-Tree format maps.   This requires the new Berkeley DB  library.

- hash

  Hash format maps.   This also requires the Berkeley DB  library.

- cdb

  CDB (Constant DataBase) format maps.   This requires the tinycdb library.

- implicit

  The first available format in the following order: hash, dbm, and cdb.

In all cases, **makemap** reads lines from the standard input consisting of two  words separated by white space.   The first is the database key,  the second is the value.   The value may contain  \`\`%*n*''  strings to indicate parameter substitution.   Literal percents should be doubled  (\`\`%%''). Blank lines and lines beginning with \`\`#'' are ignored.

Notice: do **not** use **makemap** to create the aliases data base, but **newaliases** which puts a special token into the data base that is required by **sendmail.**

If the *TrustedUser* option is set in the sendmail configuration file and **makemap** is invoked as root, the generated files will be owned by  the specified *TrustedUser.*

### Flags

- **-C**

  Use the specified **sendmail** configuration file for looking up the TrustedUser option.

- **-N**

  Include the null byte that terminates strings  in the map.   This must match the -N flag in the sendmail.cf  \`\`K'' line.

- **-c**

  Use the specified hash and B-Tree cache size.

- **-D**

  Use to specify the character to use to indicate a comment (which is ignored) instead of the default of '#'.

- **-d**

  Allow duplicate keys in the map.   This is only allowed on B-Tree format maps.   If two identical keys are read,  they will both be inserted into the map.

- **-e**

  Allow empty value (right hand side).

- **-f**

  Normally all upper case letters in the key  are folded to lower case.   This flag disables that behaviour.   This is intended to mesh with the  -f flag in the  **K** line in sendmail.cf.   The value is never case folded.

- **-i**

  Use the specified type as fallback if the given *maptype* is not available.

- **-l**

  List supported map types.

- **-o**

  Append to an old file.   This allows you to augment an existing file. Note: this might not be supported by all database types, e.g., cdb.

- **-r**

  Allow replacement of existing keys.   Normally **makemap** complains if you repeat a key,  and does not do the insert.

- **-s**

  Ignore safety checks on maps being created.   This includes checking for hard or symbolic  links in world writable directories.

- **-t**

  Use the specified delimiter instead of white space (also for dumping a map).

- **-u**

  dump (unmap) the content of the database to standard output.

- **-v**

  Verbosely print what it is doing.

## Example

makemap hash /etc/mail/access \< /etc/mail/access

## SEE ALSO

[sendmail(8)](/sendmail/8.md), [newaliases(1)](/newaliases/1.md)

## HISTORY

The **makemap** command appeared in  4.4BSD.