Libc-320.tar.gz

[apple/libc.git] / stdlib / FreeBSD / twalk.c

diff --git a/stdlib/FreeBSD/twalk.c b/stdlib/FreeBSD/twalk.c
new file mode 100644 (file)
index 0000000..516ef44
--- /dev/null
+++ b/stdlib/FreeBSD/twalk.c
@@ -0,0 +1,58 @@
+/*     $NetBSD: twalk.c,v 1.1 1999/02/22 10:33:16 christos Exp $       */
+
+/*
+ * Tree search generalized from Knuth (6.2.2) Algorithm T just like
+ * the AT&T man page says.
+ *
+ * The node_t structure is for internal use only, lint doesn't grok it.
+ *
+ * Written by reading the System V Interface Definition, not the code.
+ *
+ * Totally public domain.
+ */
+
+#include <sys/cdefs.h>
+#if 0
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: twalk.c,v 1.1 1999/02/22 10:33:16 christos Exp $");
+#endif /* LIBC_SCCS and not lint */
+#endif
+__FBSDID("$FreeBSD: src/lib/libc/stdlib/twalk.c,v 1.5 2003/01/05 02:43:18 tjr Exp $");
+
+#define _SEARCH_PRIVATE
+#include <search.h>
+#include <stdlib.h>
+
+static void trecurse(const node_t *,
+    void (*action)(const void *, VISIT, int), int level);
+
+/* Walk the nodes of a tree */
+static void
+trecurse(root, action, level)
+       const node_t *root;     /* Root of the tree to be walked */
+       void (*action)(const void *, VISIT, int);
+       int level;
+{
+
+       if (root->llink == NULL && root->rlink == NULL)
+               (*action)(root, leaf, level);
+       else {
+               (*action)(root, preorder, level);
+               if (root->llink != NULL)
+                       trecurse(root->llink, action, level + 1);
+               (*action)(root, postorder, level);
+               if (root->rlink != NULL)
+                       trecurse(root->rlink, action, level + 1);
+               (*action)(root, endorder, level);
+       }
+}
+
+/* Walk the nodes of a tree */
+void
+twalk(vroot, action)
+       const void *vroot;      /* Root of the tree to be walked */
+       void (*action)(const void *, VISIT, int);
+{
+       if (vroot != NULL && action != NULL)
+               trecurse(vroot, action, 0);
+}