OSF DCE Application Development Guide--Core Components

DCE Application Messaging
Each line in a sams file consists of a simple header and value combination. The header
indicates the meaning of the value being specified, and value is the value itself. A sams
file for messaging use is normally made up of three parts (although only two parts are
needed for the short example in this chapter). The first part consists of a minimum of one
line that specifies the name of the component (that is, the application) that is to use the
messages that will be generated from the file.
Each invocation of sams to process a separate .sams input file produces a complete set of
output files that can be used by the DCE messaging routines to print or log messages as
required. These ‘‘sets’’ of output files are organized by DCE component. (In DCE itself,
these components are identical to the DCE components: RPC, DTS, and so on; for
applications, the categorization of components is determined by the developer.) Each set
of output files will have names in which the component name (also determined by the
developer) appears.
The component name that you specify at the top of a sams file must consist of a three-
character (no more, no less) string. For the ‘‘Hello World’’ program we will use the
component name hel:
# Part I of simple sams message file...
component hel
The hel string will be used to identify all the files and data structures that sams will
generate from the file.
The second (and final) part of a sams file for DCE messaging consists of a series of
records that specify the messages themselves. Each record is delimited by the start and
end keywords. Within each record, a series of keywords identifies the various
information that each message consists of or has associated with it.
Our file will contain only one message, the text of which is to be ‘‘Hello World’’. The
record that specifies it is as follows:
start
code hello_msg
text "Hello World"
action "None required"
explanation "Greeting message for sample messaging program"
end
The keywords specified have the following meanings:
code Identifies the message.
text Specifies the text of the message itself.
explanation Describes the meaning of the message. The text following this
keyword is used to generate the documentation of the component’s
messages.
action Describes any action(s) that should be taken in response to the
message. The text following this keyword is used to generate the
documentation of the component’s messages.
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