I'm required to use a special library to keep track of my memory leaks where malloc()= allocate( ) and free( ) = unallocate( ).

I'm trying to complete free a linked-list but it seems like the "root" value isn't being freed.

typedef struct _node {
    struct _node *child;
    char *command;
} Command_list;

void delete_commands(Command_list **root)
{
    Command_list *temp;
    while( *root != NULL ){
        temp = (*root)->child;
        //printf("STRING: %s\n", *root->command );
        unallocate( *root );
        *root = temp;

    }
}

The function that's calling it

void file_processing( .... ){
    Command_list *root = allocate(sizeof (Command_list));
    root = NULL;
....
        delete_commands( &root );  
    }
}

I believe that

Command_list *root = allocate(sizeof (Command_list)) 

isn't being properly de-allocated for some reason. Anyone can give me some hints?

UPDATE: I found out that instead of

Command_list *root = allocate(sizeof (Command_list));
        root = NULL;

this works:

Command_list *root = NULL;