Introduction

In the previous sections we have described ways to modify the actions of SNOMAN by adding code to user routines. As all these are based on the SNOMAN framework, all such modified versions are referred to collectively as:-

SNOMAN Applications

To get ultimate control you have to replace even this outer framework and take complete control of the entire code. Such programs are described as:-

SNOlib Applications

The outer framework consists of the following routines:-

• SNOMAN. This is the main routine. It does little more than call the main initialisation, INMAIN, the execution routines QNEXTE, and the termination routine ZEND.

• QNEXT. This the heart of the execution phase of the program. It is called once from SNOMAN (although the call goes indirectly via QNEXTE), and again every time a ZTELL signal to start a new event is received.

• ZABEND. This routine is called if a fatal error is detected. It calls ZEND.

• ZEND. This is the top level termination routine. It calls TMMAIN, the main termination routine.

When using the link_snolib tool, SNOMAN, QNEXT and ZABEND are all explicitly loaded from the SNOlib library, but ZEND is called directly by SNOMAN so needs no explicit loading. To inhibit this loading a third parameter, NO_SNOMAN, must be specified, for example:-

$SNO_TOOLS/link_snolib.scr my_main.o test.exe NO_SNOMAN
(VMS: @SNO_TOOLS:LINK_SNOLIB MY_MAIN TEST.EXE NO_SNOMAN

With these routines removed you have total power - and total responsibility! All the management provided by SU control must be provided by you!