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-rw-r--r--misc/insremque.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/misc/insremque.c b/misc/insremque.c
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+++ b/misc/insremque.c
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+/* Copyright (C) 1992 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <stddef.h>
+
+struct qelem
+  {
+    struct qelem *q_forw;
+    struct qelem *q_back;
+    char q_data[1];
+  };
+
+/* Insert ELEM into a doubly-linked list, after PREV.  */
+
+void
+DEFUN(insque, (elem, prev) ,
+      struct qelem *elem AND struct qelem *prev)
+{
+  struct qelem *next = prev->q_forw;
+  prev->q_forw = elem;
+  if (next != NULL)
+    next->q_back = elem;
+  elem->q_forw = next;
+  elem->q_back = prev;
+}
+
+/* Unlink ELEM from the doubly-linked list that it is in.  */
+
+void
+DEFUN(remque, (elem),
+      struct qelem *elem)
+{
+  struct qelem *next = elem->q_forw;
+  struct qelem *prev = elem->q_back;
+  if (next != NULL)
+    next->q_back = prev;
+  if (prev != NULL)
+    prev->q_forw = next;
+}