mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-25 11:37:56 +00:00
119 lines
3.7 KiB
Groff
119 lines
3.7 KiB
Groff
.\" $NetBSD$
|
|
.\" 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
|
|
.In search.h
|
|
.Ft void *
|
|
.Fn tdelete "const void *key" "void **rootp" "int (*compar) (const void *, const void *)"
|
|
.Ft void *
|
|
.Fn tfind "const void *key" "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.
|