bring in binary search tree code.

Obtained from: NetBSD

include/Makefile

@@ -14,7 +14,8 @@ FILES=	a.out.h ar.h assert.h bitstring.h ctype.h db.h dirent.h disktab.h \
 	limits.h link.h locale.h malloc.h memory.h mpool.h \
 	ndbm.h netdb.h nl_types.h nlist.h objformat.h \
 	paths.h pthread.h pthread_np.h pwd.h \
-	ranlib.h regex.h regexp.h resolv.h rune.h runetype.h setjmp.h sgtty.h \
+	ranlib.h regex.h regexp.h resolv.h rune.h runetype.h \
+	search.h setjmp.h sgtty.h \
 	signal.h stab.h stddef.h stdio.h stdlib.h string.h stringlist.h \
 	strings.h struct.h sysexits.h tar.h time.h timers.h \
 	ttyent.h unistd.h utime.h utmp.h vis.h

include/search.h

@@ -0,0 +1,66 @@
+/*	$NetBSD: search.h,v 1.12 1999/02/22 10:34:28 christos Exp $	*/
+/* $FreeBSD$ */
+
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>
+ * Public domain.
+ */
+
+#ifndef _SEARCH_H_
+#define _SEARCH_H_
+
+#include <sys/cdefs.h>
+#include <machine/ansi.h>
+
+#ifdef	_BSD_SIZE_T_
+typedef	_BSD_SIZE_T_	size_t;
+#undef	_BSD_SIZE_T_
+#endif
+
+typedef struct entry {
+	char *key;
+	void *data;
+} ENTRY;
+
+typedef enum {
+	FIND, ENTER
+} ACTION;
+
+typedef enum {
+	preorder,
+	postorder,
+	endorder,
+	leaf
+} VISIT;
+
+#ifdef _SEARCH_PRIVATE
+typedef struct node {
+	char         *key;
+	struct node  *llink, *rlink;
+} node_t;
+#endif
+
+__BEGIN_DECLS
+void	*bsearch __P((const void *, const void *, size_t, size_t,
+		      int (*)(const void *, const void *)));
+int	 hcreate __P((size_t));
+void	 hdestroy __P((void));
+ENTRY	*hsearch __P((ENTRY, ACTION));
+
+void	*lfind __P((const void *, const void *, size_t *, size_t,
+		      int (*)(const void *, const void *)));
+void	*lsearch __P((const void *, const void *, size_t *, size_t,
+		      int (*)(const void *, const void *)));
+void	 insque __P((void *, void *));
+void	 remque __P((void *));
+
+void	*tdelete __P((const void *, void **,
+		      int (*)(const void *, const void *)));
+void	*tfind __P((const void *, void **,
+		      int (*)(const void *, const void *)));
+void	*tsearch __P((const void *, void **, 
+		      int (*)(const void *, const void *)));
+void      twalk __P((const void *, void (*)(const void *, VISIT, int)));
+__END_DECLS
+
+#endif /* !_SEARCH_H_ */

lib/libc/stdlib/Makefile.inc

@@ -8,7 +8,7 @@ MISRCS+=abort.c abs.c atexit.c atof.c atoi.c atol.c bsearch.c calloc.c div.c \
 	exit.c getenv.c getopt.c getsubopt.c heapsort.c labs.c ldiv.c \
 	malloc.c merge.c putenv.c qsort.c radixsort.c rand.c random.c \
 	reallocf.c realpath.c setenv.c strhash.c strtol.c strtoq.c strtoul.c \
-	strtouq.c system.c
+	strtouq.c system.c tdelete.c tfind.c tsearch.c twalk.c
 
 .if ${MACHINE_ARCH} == "alpha"
 #  XXX Temporary until the assumption that a long is 32-bits is resolved
@@ -26,7 +26,7 @@ SRCS+=	strtod.c
 MAN3+=	abort.3 abs.3 alloca.3 atexit.3 atof.3 atoi.3 atol.3 bsearch.3 \
 	div.3 exit.3 getenv.3 getopt.3 getsubopt.3 labs.3 \
 	ldiv.3 malloc.3 memory.3 qsort.3 radixsort.3 rand.3 random.3 \
-	realpath.3 strtod.3 strtol.3 strtoul.3 system.3
+	realpath.3 strtod.3 strtol.3 strtoul.3 system.3 tsearch.3
 
 MLINKS+=getenv.3 putenv.3 getenv.3 setenv.3 getenv.3 unsetenv.3
 MLINKS+=qsort.3 heapsort.3 qsort.3 mergesort.3

lib/libc/stdlib/tdelete.c

@@ -0,0 +1,66 @@
+/*	$NetBSD: tdelete.c,v 1.2 1999/09/16 11:45:37 lukem Exp $	*/
+/* $FreeBSD$ */
+
+/*
+ * 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 defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: tdelete.c,v 1.2 1999/09/16 11:45:37 lukem Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#include <assert.h>
+#define _SEARCH_PRIVATE
+#include <search.h>
+#include <stdlib.h>
+
+
+/* delete node with given key */
+void *
+tdelete(vkey, vrootp, compar)
+	const void *vkey;	/* key to be deleted */
+	void      **vrootp;	/* address of the root of tree */
+	int       (*compar) __P((const void *, const void *));
+{
+	node_t **rootp = (node_t **)vrootp;
+	node_t *p, *q, *r;
+	int  cmp;
+
+	if (rootp == NULL || (p = *rootp) == NULL)
+		return NULL;
+
+	while ((cmp = (*compar)(vkey, (*rootp)->key)) != 0) {
+		p = *rootp;
+		rootp = (cmp < 0) ?
+		    &(*rootp)->llink :		/* follow llink branch */
+		    &(*rootp)->rlink;		/* follow rlink branch */
+		if (*rootp == NULL)
+			return NULL;		/* key not found */
+	}
+	r = (*rootp)->rlink;			/* D1: */
+	if ((q = (*rootp)->llink) == NULL)	/* Left NULL? */
+		q = r;
+	else if (r != NULL) {			/* Right link is NULL? */
+		if (r->llink == NULL) {		/* D2: Find successor */
+			r->llink = q;
+			q = r;
+		} else {			/* D3: Find NULL link */
+			for (q = r->llink; q->llink != NULL; q = r->llink)
+				r = q;
+			r->llink = q->rlink;
+			q->llink = (*rootp)->llink;
+			q->rlink = (*rootp)->rlink;
+		}
+	}
+	free(*rootp);				/* D4: Free node */
+	*rootp = q;				/* link parent to new node */
+	return p;
+}

lib/libc/stdlib/tfind.c

@@ -0,0 +1,47 @@
+/*	$NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $	*/
+/* $FreeBSD$ */
+
+/*
+ * 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 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 */
+
+#include <assert.h>
+#define _SEARCH_PRIVATE
+#include <stdlib.h>
+#include <search.h>
+
+/* find a node, or return 0 */
+void *
+tfind(vkey, vrootp, compar)
+	const void *vkey;		/* key to be found */
+	void **vrootp;			/* address of the tree root */
+	int (*compar) __P((const void *, const void *));
+{
+	node_t **rootp = (node_t **)vrootp;
+
+	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;
+}

lib/libc/stdlib/tsearch.3

@@ -0,0 +1,118 @@
+.\" $NetBSD$
+.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. The name of the author may not be used to endorse or promote products
+.\"    derived from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+.\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\"	OpenBSD: tsearch.3,v 1.2 1998/06/21 22:13:49 millert Exp 
+.\" $FreeBSD$
+.\"
+.Dd June 15, 1997
+.Dt TSEARCH 3
+.Os
+.Sh NAME
+.Nm tsearch, tfind, tdelete, twalk
+.Nd manipulate binary search trees
+.Sh SYNOPSIS
+.Fd #include <search.h>
+.Ft void *
+.Fn tdelete "const void *key" "void **rootp", "int (*compar) (const void *, const void *)"
+.Ft void *
+.Fn tfind "const void *key" "const void **rootp", "int (*compar) (const void *, const void *)"
+.Ft void *
+.Fn tsearch "const void *key", "void **rootp", "int (*compar) (const void *, const void *)"
+.Ft void
+.Fn twalk "const void *root" "void (*compar) (const void *, VISIT, int)"
+.Sh DESCRIPTION
+The
+.Fn tdelete ,
+.Fn tfind ,
+.Fn tsearch ,
+and
+.Fn twalk
+functions manage binary search trees based on algorithms T and D
+from Knuth (6.2.2).  The comparison function passed in by
+the user has the same style of return values as
+.Xr strcmp 3 .
+.Pp
+.Fn Tfind
+searches for the datum matched by the argument
+.Fa key
+in the binary tree rooted at
+.Fa rootp ,
+returning a pointer to the datum if it is found and NULL
+if it is not.
+.Pp
+.Fn Tsearch
+is identical to
+.Fn tfind
+except that if no match is found,
+.Fa key
+is inserted into the tree and a pointer to it is returned.  If
+.Fa rootp
+points to a NULL value a new binary search tree is created.
+.Pp
+.Fn Tdelete
+deletes a node from the specified binary search tree and returns
+a pointer to the parent of the node to be deleted.
+It takes the same arguments as
+.Fn tfind
+and
+.Fn tsearch .
+If the node to be deleted is the root of the binary search tree,
+.Fa rootp
+will be adjusted.
+.Pp
+.Fn Twalk
+walks the binary search tree rooted in
+.fa root
+and calls the function
+.Fa action
+on each node.
+.Fa Action
+is called with three arguments: a pointer to the current node,
+a value from the enum 
+.Sy "typedef enum { preorder, postorder, endorder, leaf } VISIT;"
+specifying the traversal type, and a node level (where level
+zero is the root of the tree).
+.Sh SEE ALSO
+.Xr bsearch 3 ,
+.Xr hsearch 3 ,
+.Xr lsearch 3
+.Sh RETURN VALUES
+The
+.Fn tsearch
+function returns NULL if allocation of a new node fails (usually
+due to a lack of free memory).
+.Pp
+.Fn Tfind ,
+.Fn tsearch ,
+and
+.Fn tdelete
+return NULL if
+.Fa rootp
+is NULL or the datum cannot be found.
+.Pp
+The
+.Fn twalk
+function returns no value.

lib/libc/stdlib/tsearch.c

@@ -0,0 +1,57 @@
+/*	$NetBSD: tsearch.c,v 1.3 1999/09/16 11:45:37 lukem Exp $	*/
+/* $FreeBSD$ */
+
+/*
+ * 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 defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: tsearch.c,v 1.3 1999/09/16 11:45:37 lukem Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#include <assert.h>
+#define _SEARCH_PRIVATE
+#include <search.h>
+#include <stdlib.h>
+
+/* find or insert datum into search tree */
+void *
+tsearch(vkey, vrootp, compar)
+	const void *vkey;		/* key to be located */
+	void **vrootp;			/* address of tree root */
+	int (*compar) __P((const void *, const void *));
+{
+	node_t *q;
+	node_t **rootp = (node_t **)vrootp;
+
+	if (rootp == NULL)
+		return NULL;
+
+	while (*rootp != NULL) {	/* Knuth's T1: */
+		int r;
+
+		if ((r = (*compar)(vkey, (*rootp)->key)) == 0)	/* T2: */
+			return *rootp;		/* we found it! */
+
+		rootp = (r < 0) ?
+		    &(*rootp)->llink :		/* T3: follow left branch */
+		    &(*rootp)->rlink;		/* T4: follow right branch */
+	}
+
+	q = malloc(sizeof(node_t));		/* T5: key not found */
+	if (q != 0) {				/* make new node */
+		*rootp = q;			/* link new node to old */
+		/* LINTED const castaway ok */
+		q->key = (void *)vkey;		/* initialize new node */
+		q->llink = q->rlink = NULL;
+	}
+	return q;
+}

lib/libc/stdlib/twalk.c

@@ -0,0 +1,57 @@
+/*	$NetBSD: twalk.c,v 1.1 1999/02/22 10:33:16 christos Exp $	*/
+/* $FreeBSD$ */
+
+/*
+ * 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 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 */
+
+#include <assert.h>
+#define _SEARCH_PRIVATE
+#include <search.h>
+#include <stdlib.h>
+
+static void trecurse __P((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) __P((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) __P((const void *, VISIT, int));
+{
+	if (vroot != NULL && action != NULL)
+		trecurse(vroot, action, 0);
+}