#include <stdio.h>
#include <stdlib.h>


typedef struct a
{
	int age;
	char name[10];
} el;

int main (int argc, const char * argv[]) 
{
	int i,n;
	el *array;
	int d;

	printf("length :> ");
	scanf("%d",&n);	

	array = (el *) calloc (n,sizeof(el));

	


	printf("\nINPUT\n\n");
	for (i=0; i<n; i++)
	{
			printf("name %d. el :> ",i);
			scanf("%s", array[i]. name);
			printf("age %d. el :> ",i);
			scanf("%d",& array[i]. age);
	}
	
	printf("\nPRINTOUT\n\n");
	for (i=0; i<n; i++)
	{
			printf("%d. el :> NAME:\t%s\tAGE:\t%d\n",i, array[i]. name, array[i]. age);		
	}	
	
	d =  sizeof(array)/sizeof(el);
	
					printf("Length is :> %d",d);

	return 0;
}

d =  sizeof(array)/sizeof(el);

#include <stdlib.h>

size_t* b_element_size_ptr_( void* buf )
{
    return ( size_t* )( ( char* )buf - sizeof( size_t ) );
}

size_t* b_length_ptr_( void* buf )
{
    return ( size_t* )( ( char* )buf - ( sizeof( size_t ) << 1 ) );
}

void* b_allocate( size_t siz, size_t len )
{
    char*
        buf = malloc( siz * len + ( sizeof( size_t ) << 1 ) );
    if( buf )
    {
        buf += sizeof( size_t ) << 1;
        *b_element_size_ptr_( buf ) = siz;
        *b_length_ptr_( buf ) = len;
    }
    return buf;
}

void b_deallocate( void* buf )
{
    if( buf )
        free( b_length_ptr_( buf ) );
}

size_t b_length( void* buf )
{
    return *b_length_ptr_( buf );
}

size_t b_bytes( void* buf )
{
    return b_length( buf ) * *b_element_size_ptr_( buf );
}

#include <stdio.h>

int main( void )
{
    int*
        data = b_allocate( sizeof( int ), 1024 );
    if( data )
    {
        printf( "Length of data: %d\n", b_length( data ) );
        printf( "Size (in bytes): %d\n", b_bytes( data ) );
    }
    b_deallocate( data );
    return 0;
}