8.2 Configuration Lines
Selected configuration file lines can be entered in rule-testing
mode. They will behave just as they do when being read from the
configuration file. For V8.8 sendmail and above,
three configuration commands are honored:
- #
-
Commands that begin with a # are treated as
comments and ignored. Blank lines are also ignored.
- D
-
The D configuration command (Section 21.3) is used to define a
sendmail macro. Both single-character and
multicharacter sendmail macro names can be used.
- C
-
The C configuration command (Section 22.1) is used to add a value to a class. Both
single-character and multicharacter class names can be used.
The # can begin a
line. The other two configuration commands in rule-testing mode must
begin with a dot:
.D{ntries} 23
.Cw localhost
Failure to use a dot will produce this error message:
Undefined ruleset Cw
The use of any character other than the two listed will produce this
error:
Unknown "." command .bad command here
To get a usage message, just type a dot:
> .
Usage: .[DC]macro value(s)
8.2.1 Define a Macro with .D
The .D
rule-testing command is used to define a
sendmail macro. One use for this command might
be to modify a rule that depends on the $&
prefix (Section 21.5.3). For example, consider this
small configuration file that contains a rule in
parse rule set 0 that is intended to deliver a
local user's address via the
local delivery agent:
V10
Sparse=0
R$+ $#local $@ $&X $: $1
If $X has a value, this rule returns that value as
the host (the $@) part of a
parse rule set 0 triple (Section 19.5). If $X lacks a value, the
host part is empty. This technique is useful because the
$@ part with the local delivery
agent is used to implement plussed users (Section 12.4.4).
This scheme can be tested in rule-testing mode by first specifying a
local user with $X undefined:
% /usr/sbin/sendmail -bt -Ctest.cf
ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter <ruleset> <address>
> parse bob
parse input: bob
parse returns: $# local $@ $: bob
This form of rule testing and the output produced are described in
detail in Section 8.6. Here, it is important only to
note that the host part of the triple (the $@
part) is empty.
Now, use the .D command to give
$X the value home:
> .DXhome
Now, test those rules again:
> parse bob
parse input: bob
parse returns: $# local $@ home $: bob
This time the host part of the triple (the $@
part) has the value home as intended.
The .D command can also be used to redefine the
value of existing sendmail macros. It cannot,
however, be used to redefine sendmail macros
used in rules (except for $&) because those
macros are expanded as rules are read from the configuration file
(Section 21.5.2). Also see Section 8.3.1, which describes how to view
sendmail macro values in rule-testing mode.
8.2.2 Add to a Class with .C
The .C
rule-testing command is used to add a member to a class. If the class
does not exist, it is created. One possible use for this command
would be to test whether adding a member to $=w
will have the effect you desire. For example, suppose that a new
alias called mailhub has been created for the
local host. In the following, we test sendmail
to see whether it will detect that new name as local:
% /usr/sbin/sendmail -bt
ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter <ruleset> <address>
> canonify,parse bob@mailhub
canonify input: bob @ mailhub
Canonify2 input: bob < @ mailhub >
Canonify2 returns: bob < @ mailhub >
canonify returns: bob < @ mailhub >
parse input: bob < @ mailhub >
Parse0 input: bob < @ mailhub >
Parse0 returns: bob < @ mailhub >
ParseLocal input: bob < @ mailhub >
ParseLocal returns: bob < @ mailhub >
Parse1 input: bob < @ mailhub >
MailerToTriple input: < > bob < @ mailhub >
MailerToTriple returns: bob < @ mailhub >
Parse1 returns: $# esmtp $@ mailhub $: bob < @ mailhub >
parse returns: $# esmtp $@ mailhub $: bob < @ mailhub >
This form of rule testing and the output that is produced are
described in detail in Section 8.6. Here, merely
note that the esmtp delivery agent was selected,
suggesting that mailhub was not automatically
recognized as local.
One way to fix this is to add mailhub to the
class $=w ($=w). In
rule-testing mode this can be done by using the .C
command:
> .Cw mailhub
Now, feed sendmail the same rules and address as
before to see whether this fixed the problem:
> canonify,parse bob@mailhub
canonify input: bob @ mailhub
Canonify2 input: bob < @ mailhub >
Canonify2 returns: bob < @ mailhub . >
canonify returns: bob < @ mailhub . >
parse input: bob < @ mailhub . >
Parse0 input: bob < @ mailhub . >
Parse0 returns: bob < @ mailhub . >
ParseLocal input: bob < @ mailhub . >
ParseLocal returns: bob < @ mailhub . >
Parse1 input: bob < @ mailhub . >
Parse1 returns: $# local $: bob
parse returns: $# local $: bob
Success! Adding mailhub to the class
$=w fixed the problem. You could now make that
change permanent by editing your mc file and
using that to create a new configuration file, or by adding the name
to the /etc/mail/local-host-names file
(FEATURE(use_cw_file)).
Another use for .C would include trying out
masquerading for a subdomain (FEATURE(limited_masquerade)). See also
Section 8.3.2 for a way to print the members of a
class while in rule-testing mode.
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