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-rw-r--r--lib/libc/stdlib/tfind.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/lib/libc/stdlib/tfind.c b/lib/libc/stdlib/tfind.c
new file mode 100644
index 000000000000..5fa35f1bd85f
--- /dev/null
+++ b/lib/libc/stdlib/tfind.c
@@ -0,0 +1,46 @@
+/* $NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $ */
+
+/*
+ * Tree search generalized from Knuth (6.2.2) Algorithm T just like
+ * the AT&T man page says.
+ *
+ * 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: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $");
+#endif /* LIBC_SCCS and not lint */
+#endif
+#define _SEARCH_PRIVATE
+#include <stdlib.h>
+#include <search.h>
+
+/*
+ * find a node, or return 0
+ *
+ * vkey - key to be found
+ * vrootp - address of the tree root
+ */
+posix_tnode *
+tfind(const void *vkey, posix_tnode * const *rootp,
+ int (*compar)(const void *, const void *))
+{
+
+ if (rootp == NULL)
+ return NULL;
+
+ while (*rootp != NULL) { /* T1: */
+ int r;
+
+ if ((r = (*compar)(vkey, (*rootp)->key)) == 0) /* T2: */
+ return *rootp; /* key found */
+ rootp = (r < 0) ?
+ &(*rootp)->llink : /* T3: follow left branch */
+ &(*rootp)->rlink; /* T4: follow right branch */
+ }
+ return NULL;
+}