The following example shows a Pascal program that calls the
    C RTL using the VAXC$CRTL_INIT function:

    On OpenVMS Alpha systems:

    $ PASCAL EXAMPLE
    $ LINK EXAMPLE,SYS$LIBRARY:VAXCRTL/LIB
    $ TY EXAMPLE.PAS
    PROGRAM TESTC(input, output);
    PROCEDURE VAXC$CRTL_INIT; extern;
    BEGIN
       VAXC$CRTL_INIT;
    END
    $

    A shareable image need only call this function if it contains
    an VSI C function for signal handling, environment variables,
    I/O, exit handling, a default file protection mask, or if it is a
    child process that should inherit context.

    Although many of the initialization activities are performed
    only once, DECC$CRTL_INIT can safely be called multiple times. On
    OpenVMS VAX systems, DECC$CRTL_INIT establishes the C RTL
    internal OpenVMS exception handler in the frame of the routine
    that calls DECC$CRTL_INIT each time DECC$CRTL_INIT is called.

    At least one frame in the current call stack must have that
    handler established for OpenVMS exceptions to get mapped to UNIX
    signals.