It is intended that applications which call Starlink libraries may be run without further preparation once the Starlink login file has been executed using the command:5
However, additional logical name definitions (e.g. for include files, etc.) will usually be needed if software development is planned. Each library should therefore provide a DCL command file whose purpose is to define any logical names and/or DCL symbols needed when developing software which calls the library.
This file should reside in the library directory and a DCL global symbol of the following standard form:
should be defined in order to execute it. This symbol should be defined by means of a suitable command in the Starlink login file SSC:LOGIN.COM, such as:
where LIB_DEV.COM is the command file in question (this file name is recommended for future use but existing files which serve the same purpose need not be changed).
Other software may test for the existence or non-existence of the LIB_DEV symbol in order to determine whether a library is installed in a form which allows software development.
A software developer wishing to make use of the library’s facilities should first execute the command:
to set up the appropriate development environment. A sequence of such commands might typically be placed in a LOGIN.COM file in order to define a programming environment which is used frequently. Pre-defined programming environments such as ADAM may also make use of these commands in their own startup procedures. To facilitate this type of use, a library’s startup file should ensure that if the command issued is of the form:
then the presence of “NOLOG” as the first parameter will suppress the output of any informational message. Otherwise, library startup files may optionally send messages to SYS$OUTPUT when they are executed in order to identify themselves.
5Except that ADAM applications will also require the $ADAMSTART command.