sendmail, 4th Edition

Dump a Defined Macro with $

The $ rule-testing command causes sendmail to print the value of a defined sendmail macro. The form for this command looks like this:

$X               ← show value of the single-character macro name X
${YYY}           ← show value of the multicharacter macro name YYY

Only one sendmail macro can be listed per line. If more than one is listed, all but the first are ignored:

$X $Y
    ↑
   ignored

One use for this command might be in solving the problem of duplicate domains. For example, suppose you just installed a new configuration file and discovered that your host was no longer known as here.our.domain, but instead wrongly had an extra domain attached, like this: here.our.domain.our.domain. To check the value of $j ($j on page 830) which should contain the canonical name of your host, you could run sendmail in rule-testing mode:

ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter <ruleset> <address>
> $j
$w.our.domain
>

This looks right because $w ($w on page 850) is supposed to contain our short hostname. But just to check, you could also print the value of $w:

> $w
here.our.domain

Aha! Somehow, $w got the full canonical name. A quick scan of your .mc file (Configure with m4 on page 587) turns up this error:

LOCAL_CONFIG
Dwhere.our.domain           # $w is supposed to be full -- joachim

Apparently, your assistant, Joachim, mistakenly thought the new sendmail was wrong. You can take care of the configuration problem by deleting the offending line and creating a new configuration file. To solve ...