Class with m4
In configuring with the m4 technique, many classes are defined for your convenience. You need to be aware of these not only to take advantage of them, but also to avoid reusing their single-character names by mistake. Table 32.1 lists all the macros that the m4 technique uses as of version 8.8.4. Most are described in other sections, but a few are described here. See LOCAL-CONFIG for the general method used for adding members and new class names using the m4 technique.
| Class | Description | |
|---|---|---|
| $=B | FEATURE(bestmx-is-local) | Domains to lookup in bestmx in place of $=w
|
| $=E | EXPOSED-USER | List of EXPOSED USERS users |
| $=F | Berkeley example mc files | |
| $=G | FEATURE(genericstable) | List of other sites to look up in genericstable |
| $=L | LOCAL-USER | List of LOCAL USER users |
| $=M | FEATURE(limited-masquerade) | List of hosts to masquerade |
| $=O | here | List nonusername characters |
| $=P | here | List of pseudo domains |
| $=U | "UUCP" | Locally connected UUCP hosts |
| $=V | Hosts connected to UUCP relay $V | |
| $=W | Hosts connected to UUCP relay $W | |
| $=X | Hosts connected to UUCP relay $X | |
| $=Y | Locally connected smart UUCP hosts | |
| $=Z | Locally connected domainized UUCP hosts |
The class O is used by the m4 technique to hold a list of characters that cannot be used in local usernames. This list is used to detect certain kinds of routing addresses that might otherwise be difficult to detect. This list initially contains
@ %
but may also contain a ! if UUCP support is included.
The class P holds a list of pseudo domains that will not be looked up using DNS. Unless you use a FEATURE, this class will only contain a dot. Various FEATUREs will add appropriate pseudo domains to it, such as .UUCP and .REDIRECT.