1995-12-28 11:51:55 +03:00
|
|
|
.\" $NetBSD: realloc.3,v 1.4 1995/12/28 08:52:45 thorpej Exp $
|
|
|
|
|
.\"
|
1993-03-21 12:45:37 +03:00
|
|
|
.\" Copyright (c) 1991 The Regents of the University of California.
|
|
|
|
|
.\" 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. All advertising materials mentioning features or use of this software
|
|
|
|
|
.\" must display the following acknowledgement:
|
|
|
|
|
.\" This product includes software developed by the University of
|
|
|
|
|
.\" California, Berkeley and its contributors.
|
|
|
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
|
|
|
.\" may be used to endorse or promote products derived from this software
|
|
|
|
|
.\" without specific prior written permission.
|
|
|
|
|
.\"
|
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
|
|
|
|
|
.\"
|
1993-08-01 11:42:49 +04:00
|
|
|
.\" from: @(#)realloc.3 5.1 (Berkeley) 5/2/91
|
1993-03-21 12:45:37 +03:00
|
|
|
.\"
|
|
|
|
|
.Dd May 2, 1991
|
|
|
|
|
.Dt REALLOC 3
|
|
|
|
|
.Os
|
|
|
|
|
.Sh NAME
|
|
|
|
|
.Nm realloc
|
|
|
|
|
.Nd reallocation of memory function
|
|
|
|
|
.Sh SYNOPSIS
|
|
|
|
|
.Fd #include <stdlib.h>
|
|
|
|
|
.Ft void *
|
|
|
|
|
.Fn realloc "void *ptr" "size_t size"
|
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
|
The
|
|
|
|
|
.Fn realloc
|
|
|
|
|
function changes the size of the object pointed to by
|
|
|
|
|
.Fa ptr
|
|
|
|
|
to the size specified by
|
|
|
|
|
.Fa size .
|
|
|
|
|
The contents of the object are unchanged up to the lesser
|
|
|
|
|
of the new and old sizes.
|
|
|
|
|
If the new size is larger, the value of the newly allocated portion
|
|
|
|
|
of the object is indeterminate.
|
|
|
|
|
If
|
|
|
|
|
.Fa ptr
|
|
|
|
|
is a null pointer, the
|
|
|
|
|
.Fn realloc
|
|
|
|
|
function behaves like the
|
|
|
|
|
.Xr malloc 3
|
|
|
|
|
function for the specified size.
|
|
|
|
|
Otherwise, if
|
|
|
|
|
.Fa ptr
|
|
|
|
|
does not match a pointer earlier returned by the
|
|
|
|
|
.Xr calloc 3 ,
|
|
|
|
|
.Xr malloc 3 ,
|
|
|
|
|
or
|
|
|
|
|
.Fn realloc
|
|
|
|
|
function, or if the space has been deallocated
|
|
|
|
|
by a call to the
|
|
|
|
|
.Xr free
|
|
|
|
|
or
|
|
|
|
|
.Fn realloc
|
|
|
|
|
function, unpredictable and usually detrimental
|
1994-01-11 02:32:20 +03:00
|
|
|
behavior will occur.
|
1993-03-21 12:45:37 +03:00
|
|
|
If the space cannot be allocated, the object
|
|
|
|
|
pointed to by
|
|
|
|
|
.Fa ptr
|
|
|
|
|
is unchanged.
|
|
|
|
|
If
|
|
|
|
|
.Fa size
|
|
|
|
|
is zero and
|
|
|
|
|
.Fa ptr
|
|
|
|
|
is not a null pointer, the object it points to is freed.
|
|
|
|
|
.Pp
|
|
|
|
|
The
|
|
|
|
|
.Fn realloc
|
|
|
|
|
function returns either a null pointer or a pointer
|
|
|
|
|
to the possibly moved allocated space.
|
|
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr alloca 3 ,
|
|
|
|
|
.Xr calloc 3 ,
|
|
|
|
|
.Xr free 3 ,
|
|
|
|
|
.Xr malloc 3 ,
|
|
|
|
|
.Sh STANDARDS
|
|
|
|
|
The
|
|
|
|
|
.Fn realloc
|
|
|
|
|
function conforms to
|
|
|
|
|
.St -ansiC .
|
