xtrealloc(3) [hpux man page]

XtRealloc()															       XtRealloc()

Name
  XtRealloc - change the size of an allocated block of storage.

Synopsis
  char *XtRealloc(ptr, num);
	 char *ptr;
	 Cardinal num;

Inputs
  ptr	    Specifies a pointer to memory allocated with XtMalloc(), XtCalloc(), or XtRealloc(), or NULL.

  num	    Specifies the new number of bytes of memory desired in the block.

Returns
  A pointer to allocated memory.

Description
  XtRealloc() changes the size of the block of allocated memory pointed to by ptr to be at least num bytes large.  In order to make this size
  change, it may have to allocate a new block of memory and copy the contents of the old block (or as much as will fit) into the  new  block.
  If  it  allocates a new block of memory, it frees the old block.  In either case, it returns a pointer to a block of memory which is of the
  requested size.  If there is insufficient memory to allocate the new block, XtRealloc() terminates by calling XtErrorMsg().

  If ptr is NULL, XtRealloc() simply calls XtMalloc() to allocate a block of memory of the requested size.

Usage
  Note that XtRealloc() may move the contents of your allocated memory to a new location; the return value may or may not be the same as ptr.
  Not  all  memory can be safely reallocated.  If there are multiple pointers to a block of memory scattered through out an application (such
  as pointers to a widget record), then reallocating that memory is not safe, because all pointers to it cannot  be  updated.	Other  memory
  (such  as  the array of children maintained privately by the Composite widget class) can be safely updated because there should be only one
  pointer to it in the application (in this case the pointer is the composite.children field of the widget).  These cautions are no different
  than those required with the standard realloc() function.

  In most cases, you will have to cast the return value of XtRealloc() to an appropriate pointer type.

  Note that because XtRealloc() behaves like XtMalloc() when passed a NULL pointer, (something that realloc() does not do), you don't have to
  write special case code to allocate the first chunk of memory with XtMalloc() and subsequent chunks with XtRealloc(); you  can  simply  use
  XtRealloc() everywhere.

  Memory  allocated with XtRealloc() must be deallocated with XtFree().  The function XtRealloc() is implemented by the Toolkit independently
  of the particular environment, so programs ported to a system not supporting malloc will still work.

See Also
  XtCalloc(1), XtFree(1), XtMalloc(1), XtNew(1), XtNewString(1).

Xt - Memory Allocation														       XtRealloc()

Check Out this Related Man Page

XtMalloc(3)							   XT FUNCTIONS 						       XtMalloc(3)

NAME

       XtMalloc, XtCalloc, XtRealloc, XtFree, XtNew, XtNewString - memory management functions

SYNTAX

       char *XtMalloc(Cardinal size);

       char *XtCalloc(Cardinal num, Cardinal size);

       char *XtRealloc(char *ptr, Cardinal num);

       void XtFree(char *ptr);

       type *XtNew(type);

       String XtNewString(String string);

ARGUMENTS

       num	 Specifies the number of bytes or array elements.

       ptr	 Specifies a pointer to the old storage or to the block of storage that is to be freed.

       size	 Specifies the size of an array element (in bytes) or the number of bytes desired.

       string	 Specifies a previously declared string.

       type	 Specifies a previously declared data type.

DESCRIPTION

       The XtMalloc functions returns a pointer to a block of storage of at least the specified size bytes.  If there is insufficient memory to
       allocate the new block, XtMalloc calls XtErrorMsg.

       The XtCalloc function allocates space for the specified number of array elements of the specified size and initializes the space to zero.
       If there is insufficient memory to allocate the new block, XtCalloc calls XtErrorMsg.

       The XtRealloc function changes the size of a block of storage (possibly moving it).  Then, it copies the old contents (or as much as will
       fit) into the new block and frees the old block.  If there is insufficient memory to allocate the new block, XtRealloc calls XtErrorMsg.
       If ptr is NULL, XtRealloc allocates the new storage without copying the old contents; that is, it simply calls XtMalloc.

       The XtFree function returns storage and allows it to be reused.	If ptr is NULL, XtFree returns immediately.

       XtNew returns a pointer to the allocated storage.  If there is insufficient memory to allocate the new block, XtNew calls XtErrorMsg.
       XtNew is a convenience macro that calls XtMalloc with the following arguments specified:

       ((type *) XtMalloc((unsigned) sizeof(type))

       XtNewString returns a pointer to the allocated storage.	If there is insufficient memory to allocate the new block, XtNewString calls XtEr-
       rorMsg.	XtNewString is a convenience macro that calls XtMalloc with the following arguments specified:

       (strcpy(XtMalloc((unsigned) strlen(str) + 1), str))

SEE ALSO

       X Toolkit Intrinsics - C Language Interface
       Xlib - C Language X Interface

X Version 11							    libXt 1.0.5 						       XtMalloc(3)

Linux and UNIX Man Pages

xtrealloc(3) [hpux man page]

Check Out this Related Man Page