Text describing the error is also logged and will appear in this output.
Rule set debug_dumpstate is called withan empty workspace. After the debug_dumpstate rule
set is done, each token in the resulting new workspace is printed, one per line. This gives
you a hook into the internals of sendmail, enabling you to display information that might
otherwise be invisible. For example, consider the desire to display identd information, the
current sender??™s address, and the current queue identifier:
Sdebug_dumpstate
R$* $@ $&_ $&s $&i
Here, the $* in the LHS matches the zero tokens passed to the debug_dumpstate rule set.
The $@ prefix in the RHS suppresses recursion. Each of the three sendmail macros that
follows is stated witha $& prefix (?§21.5.3 on page 793) that prevents each from being
prematurely expanded when the configuration file is first read.
Another example might involve the need to look up the current recipient??™s host with DNS:
Sdebug_dumpstate
R$* $@ $[ $&h $]
* In V8.7 sendmail, this is rule set 89. Beginning with V8.8 sendmail, rule sets 80 through 89 are reserved for
use by vendors, such as Sun Microsystems.
This is the Title of the Book, eMatter Edition
Copyright ?© 2007 O??™Reilly & Associates, Inc. All rights reserved.
512 | Chapter 14: Signals, Transactions, and Syslog
The $[ and $] operators (?§18.7.
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