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The Question is: In most flavors of UNIX (and also NT), there is the availability of "init/exit" routines on shared libraries. These routines (which are also on Dec Unix) allow certain routines to be executed before the main function is called. In the case of Dec Unix, the entry symbol is __init_ and the exit symbol is __fini_. These symbols are user definable via the linker. An example would be like as follows cc test.c -init init_proc -fini exit_proc (where the linker is passed -init <procedure_name> -fini <procedure_name>). The order of operations would then become : init_proc main exit_proc Is there any way of doing the same thing? This is expecially useful again when someone links up to your shared image. This way you can hide variables and such from the programmer (so he doesn't have to deal with them). Any information would be extremly useful, Chris The Answer is : Please see the lib$initialize program section (psect) documentation for information on the image initialization support -- this is likely the most direct analog to the UNIX mechanism cited in your question. This is introduced in the OpenVMS Programming Concepts manual, with additional information elsewhere in the OpenVMS documentation set. OpenVMS applications perform cleanup operations using a program-declared exit handler, using the sys$dclexh system service or the C atend() call. Mechanisms such as user-written exit handlers and signal handlers can be bypassed, depending on activity within the image and on activity of the user (such as a <CTRL/Y> followed by STOP). Under most circumstances, the exit handlers and signal handlers are invoked when the image is run down. User-written system services include an inner-mode (privileged mode) image rundown routine in the PLV structure that is run at all times. This mechanism cannot be bypassed. Entry and exit routines can also be included via the debugger bootstrap mechanism -- a standard or user-written debugger can gain control prior to the main image, and regains control again when the image exits. This mechanism is less commonly used, but is another direct analog to your question. (You can also use lib$signal() of SS$_DEBUG to activate and pass commands to the standard OpenVMS debugger -- these program-requested debugger commands can be used for various purposes.)
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