TCP/IP Configuration and Management Manual

Configuring the NonStop TCP/IP Subsystem
TCP/IP Configuration and Management Manual—427132-004
3-47
Simple Mail Transfer Protocol (SMTP)
Tokens beginning with a dollar sign are expanded according to the following
metasymbols:
The $n syntax substitutes the corresponding value from a $+, $*, $=, or $~ match on
the left-hand side. You may use $n syntax anywhere.
A host name enclosed between $[ and $] is looked up using the sockets library
routines and replaced by the canonical name. For example, $[csam$] would become
lbl-csam.arpa and $[[128.32.130.2]$] would become vangogh.BigCityU.edu.
The $>n syntax causes the remainder of the line to be substituted as usual, then
passed as the argument to rule set n. The final value of rule set n then becomes the
substitution for this rule.
For example:
R@$+,$+:$+ @$1:$2:$3 # change all "," to ":"
R@$+:$+ $@$>6<@$1>:$2 # src route is canonical
The second line indicates that rule set 6 must be used next.
Use the $# syntax only in rule set zero. $# syntax causes rule-set evaluation to
terminate immediately and signals to the mailer that the address has been completely
resolved. The complete syntax is as follows:
$#mailer$@host$:user
This syntax specifies the {mailer, host, user} information necessary to direct the mailer.
If the mailer is local, you may omit the host part. The mailer and host must be a single
word but the user may consist of multiple parts.
A right-hand side may be preceded by a $@ or a $: to control evaluation. A $@ prefix
causes the rule set to return with the remainder of the right-hand side as the value. A
$: prefix terminates the rule immediately but sets the rule set to continue. Use this
prefix to avoid the continued application of a rule. The prefix is stripped before
continuing.
The $@ and $: prefixes may precede a $> specification. For example:
R$+ $:$>7$1
matches anything, passes what it matches to rule set seven, and continues. The $: is
necessary to avoid an infinite loop.
$n Substitute indefinite token n from the left-hand side
$[name$] Canonicalize name
$>n Call rule set n
$@host Specify host
$:user Specify user
$#mailer Specify mailer