> Another thing you get is automation support. Once you can
> recognize specific messages, you can respond to their appearance.
> Mainframe systems have lots of software options for analyzing
> system message streams (data similar to klogd's and syslogd's),
> and for initiating actions based on that information, often
> without human intervention or oversight. Most of that automation
> is keyed to the message identifier, since that's a distinct
> value that doesn't change when messages are translated into
> different languages.
Ok now that bit does have an equivalent in its own unix think. Unix programs
make heavy use of error codes when they exit. Thus you'll find the man
pages fairly religiously document the error codes on exit (an extreme
example being sendmail)...
Sendmail returns an exit status describing what it did.
The codes are defined in <sysexits.h>:
EX_OK Successful completion on all addresses.
EX_NOUSER
User name not recognized.
EX_UNAVAILABLE
Catchall meaning necessary resources were not
available.
EX_SYNTAX
Syntax error in address.
EX_SOFTWARE
Internal software error, including bad arguments.
[etc...]
