rom/exec/remhead.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Remove the first node of a list
   6     Lang: english
   7 */
   8
   9 #include <aros/debug.h>
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <exec/lists.h>
  15 #include <proto/exec.h>
  16
  17         AROS_LH1I(struct Node *, RemHead,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct List *, list, A0),
  21
  22 /*  LOCATION */
  23         struct ExecBase *, SysBase, 43, Exec)
  24
  25 /*  FUNCTION
  26         Remove the first node from a list.
  27
  28     INPUTS
  29         list - Remove the node from this list
  30
  31     RESULT
  32         The node that has been removed.
  33
  34     NOTES
  35
  36     EXAMPLE
  37         struct List * list;
  38         struct Node * head;
  39
  40         // Remove node and return it
  41         head = RemHead (list);
  42
  43     BUGS
  44
  45     SEE ALSO
  46
  47     INTERNALS
  48
  49 ******************************************************************************/
  50 {
  51     AROS_LIBFUNC_INIT
  52     struct Node * node;
  53
  54     ASSERT(list != NULL);
  55     /*
  56         Unfortunately, there is no (quick) check that the node
  57         is in a list
  58     */
  59
  60     /* Get the address of the first node or NULL */
  61     node = list->lh_Head->ln_Succ;
  62     if (node)
  63     {
  64         node->ln_Pred = (struct Node *)list;
  65         node = list->lh_Head;
  66         list->lh_Head = node->ln_Succ;
  67     }
  68
  69     /* Return the address or NULL */
  70     return node;
  71     AROS_LIBFUNC_EXIT
  72 } /* RemHead */
  73