sendmail, 4th Edition

Create Files with makemap

The makemap program, supplied in source form with V8 sendmail, is fully described in The makemap Program on page 370. It is used to create database files and is run, in brief, from the command line like this:

% makemap type file < textfile

The type can be either dbm (which uses the ndbm(3) library routines), hash, or btree (both of which use the db(3) library routines). The file is the location and name (full path or relative name) for the database file to create. For dbm files, the .pag and .dir suffixes are added automatically. For db files, the .db suffix will be added automatically if it is not already included in the name.

The makemap program reads from its standard input. That input is line-oriented and contains the text from which the database files will be created. 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. An example of such an input file is the following:

lady     relaysite!lady
my.host  relaysite!lady
bug      bug.localuucp

The second line in this example shows that keys can be multitokened (my.host is three tokens). In reading from existing files, some conversion might be required to massage the input into a usable form. To make a database of the /etc/hosts file (for converting hostnames into IP addresses), for example, a command line such as the following might be required:^[337]

% awk ...