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                                                        insertbefore(3C)



        _________________________________________________________________
        insertbefore                                            function
        Insert an element into a queue before another queue element.
        _________________________________________________________________


        Calling Sequence

        #include <queue.h>

        struct queue *que;
        struct element *ptr, *elem;
        ptr = insertbefore(&que, ptr, elem);


        Description

        The insert_before function inserts an element before a specific
        element in a doubly-linked list.  You must define your element in
        the program.  The first two double words of the element are
        reserved to hold the forward and backward pointers.  For example:

        struct element1 {
        int *forwardptr;
        int *backwardptr;
        char dataitem;
        } *ptr;

        The pointer that you pass to the insert_before function is the
        pointer to the element that you define and declare in the
        program.

        The insert_before function, defined in the include file queue.h,
        uses the hardware representation for queues. For more detail,
        consult The ECLIPSE 32-Bit Systems Principles of Operation.


        Returns

        The insert_before function returns the pointer inserted.


        Related Functions

        See also the insert_after, insert_head, and insert_tail
        functions.








        DG/UX 4.00                                                 Page 1
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