Ask the Wizard Questions
FORTRAN: Accessing system data from Fortran
The Question is:
1) where do I find answers to the not-so-FAQ?
Here I see some goodies from the past two months,
but where are the stuff from yesteryear?
2) Is it possible to access the system data from a FORTRAN
program (via SYS$CMEXEC, LIB$CALLG etc.)?
I want to build a profiler (like INFO from DECUS, but
on the AXP - and possibly with some more options) - and my
boss will not allow me to spend a lot of time learning MACRO
- I do bits and stuff easily in FORTRAN.
Can You recommend some litterature on the subject??
The Answer is:
It's not clear what you mean by "system data". If you're looking for
performance information (CPU time, page faults, etc.) these are all available
by calling the SYS$GETJPI system service. See the System Service Reference
Manual for details, and the DEC Fortran User Manual for help on using
system services from Fortran.
If you want access to OpenVMS internal data structures, you first need to know
what you want - the OpenVMS Internals and Data Structures book from Digital
Press can help you here. You would then declare the appropriate symbols
EXTERNAL and use the POINTER statement to get access to data at the external
symbol's address. This is not novice-level programming and we do not
recommend jumping into this if you are not thoroughly familiar with the