rmvb(D3)

NAME
     rmvb - remove a message block from a message

SYNOPSIS
     #include <sys/stream.h>
     #include <sys/ddi.h>
     mblk_t *rmvb(mblk_t *mp, mblk_t *bp);

   Arguments
     mp        Pointer to the message from which a message block is to be
               removed.

     bp        Pointer to the message block to be removed.

DESCRIPTION
     rmvb removes the message block specified by bp from the message specified
     mp and returns a pointer to the altered message.

   Return Values
     On success, a pointer to the message (minus the removed block) is
     returned.  If bp was the only block in the message before rmvb was
     called, NULL is returned.  If the designated message block (bp) was not
     in the message, -1 is returned.

USAGE
     The message block is not freed, merely removed from the message.  It is
     the caller's responsibility to free the message block.

   Level
     Base or Interrupt.

   Synchronization Constraints
     Does not sleep.

     Driver-defined basic locks, read/write locks, and sleep locks may be held
     across calls to this function.

   Examples
     This routine removes all zero-length M_DATA message blocks from the given
     message.  For each message block in the message, we save the next message
     block (line 9).  If the current message block is of type M_DATA and has
     no data in its buffer (lines 10-11), then we remove the message block
     from the message (line 12) and free it (line 13).  In either case, we
     continue with the next message block (line 15), until we have checked
     every message block in the message.

      1  void
      2  xxclean(mp)
      3    mblk_t *mp;
      4  {
      5    mblk_t *tmp;
      6    mblk_t *nmp;
      7    tmp = mp;
      8    while (tmp) {
      9        nmp = tmp->b_next;
     10        if ((tmp->b_datap->db_type == M_DATA) &&
     11           (tmp->b_rptr == tmp->b_wptr)) {
     12            mp = rmvb(mp, tmp);
     13            freeb(tmp);
     14        }
     15        tmp = nmp;
     16    }
     17  }