Sendmail, 3rd Edition

The makemap Program

The makemap program is supplied in source form with V8 sendmail. It can also be supplied in pre-compiled form by your vendor.^[9] It is used to create database files and is run from the command line like this:

% makemap switches dbtype outfile < infile 

We’ll discuss the switches in the next section. The dbtype can be dbm (which uses the ndbm(3) library routines), hash, or btree (both of which use the db(3) library routines). The outfile is the location and name (full path or relative name) for the database file that will be created. For dbm files, the .pag and .dir suffixes are added automatically. For the db files, the .db suffix will be added automatically if it is not already included in the name.

The infile is the name of the input text file from which the database will be created. The makemap program reads from its standard input, hence the < character. That input is line-oriented, with one database entry per line. Lines that begin with a # are interpreted as comments and ignored. Lines that contain no characters (empty lines) are also ignored. Whitespace (spaces or tabs) separates the key on the left from the data on the right.

The following is an example of such an input file:

 key                  data 
 ↓
                     ↓
lady              relaysite!lady
my.host           relaysite!lady
bug               bug localuucp

The second line shows that keys can be multitokened (my.host is three tokens), but cannot contain space or tab characters. The data is separated from the keys by one or more space or tab characters. The last ...