Header File 

malloc.h 

Category 

Memory Routines 

Prototype 

int _rtl_heapwalk(_HEAPINFO *hi); 

Description 

Inspects the heap node by node.

_rtl_heapwalk receives a pointer to a structure of type _HEAPINFO (declared in malloc.h). Note that the _HEAPINFO structure must be allocated on the heap (using malloc()). You can’t pass the address of a variable declared on the stack. 

For the first call to _rtl_heapwalk, set the hi._pentry field to NULL. _rtl_heapwalk returns with hi._pentry containing the address of the first block.

Return Value 

This function returns one of the following values:

Example

#include <stdio.h>
#include <malloc.h>
#include <alloc.h>
#define NUM_PTRS  10
#define NUM_BYTES 16
int main( void )
{
   _HEAPINFO *hi;
   char *array[ NUM_PTRS ];
   int i;
   hi = (_HEAPINFO *) malloc( sizeof(_HEAPINFO) );
   for( i = 0; i < NUM_PTRS; i++ )
      array[ i ] = (char *) malloc( NUM_BYTES );
   for( i = 0; i < NUM_PTRS; i += 2 )
     free( array[ i ] );
   hi->_pentry = NULL;
   printf( "   Size   Status\n" );
   printf( "   ----   ------\n" );
   while( _rtl_heapwalk( hi ) == _HEAPOK )
     printf( "%7u    %s\n", hi->_size, hi->_useflag ? "used" : "free" );
   free( hi );
   return 0;
}

Portability