sendmail, 4th Edition

Look Up a Database Item with /map

The /map rule-testing command causes sendmail to look up a key in a database and print the value found (if there is one). The /map command is used like this:

/map name key

Here, name is the name of a database. It is either a name you assigned using a K configuration command (The K Configuration Command on page 882) or a name that is internally defined by sendmail, such as aliases.files (switch on page 938). The key is the item you wish to look up in the database. If both name and key are missing, sendmail prints this usage message:

Usage: /map mapname key

If just the key is missing, sendmail prints this error:

No key specified

If the name is that of a database that does not exist, sendmail prints this error:

Map named "bad name here" not found

Otherwise, the database does exist, so sendmail looks up the key in it. If the key is not found in the database, sendmail prints this:

map_lookup: name (key) no match (error number here
)

The error number corresponds to error numbers listed in the sysexits.h file.

The /map rule-testing command is very useful for testing databases of your own design. If a rule that uses the database fails to work as predicted, use /map to test that database by hand. To illustrate, consider the sampling of maps in the following sections.

The aliases database map

The aliases map is used to convert a local address into one or more new addresses. Using the rule-testing /map command, you can see how sendmail looks up an alias:

> /map aliases ...