How can multiple variables be passed to a function cleanly in C?

#Old semi-"global" variables:

function vars = f1()

    a = 1;
    b = 'hello';
    c = {[1 2 3]};
    currvars = whos;    %all variable info
    for k = 1:size(currvars, 1)
       eval(['vars.(currvars(k).name) = ' currvars(k).name ';']);
    end

end

#Function to assign variables to the calling script's/function's workspace. Variable names are determined by the single structure's fieldnames:
function setvars(func)

    vars = func;
    protected = {'If needed, put variable names you do not want here'};
    names    = fieldnames(vars);
    newnames = genvarname(names, protected);
    for k = 1:numel(newnames)
        assignin('caller', newnames{k}, vars.(names{k}));
    end

end

#Script call:

setvars(f1);

def func1 ():
  a = 1
  b = 2
  return a,b

def func2 (a, b):
  c = 3
  d = 4
  e = a * c
  f = b + d

a, b = func1()
print(a, b)
func2(a, b)

>>> a, b = func1()
>>> print(a, b)
1 2
>>> func2(a, b)

$parameters["price"]=array("sort_by"=>"_auto_price","order_by"=>"meta_value_num");
$parameters["year"] =array("sort_by"=>"_auto_year","order_by"=>"meta_value");
// Same for other parameters

$sorting = $parameters[$sortby]["sort_by"];
$orderby = $parameters[$sortby]["order_by"];

$sortby = $_GET['sort'] or $sortby = 'price';

 $sortby = isset($_GET['sort']) ? $_GET['sort'] : 'price';

var myAppVar = {};
window.addEventListener('load', function() {
  myAppVar.var_1 = localStorage.getItem('var_1');
  ...
}

def my_func(input_1: set, input_2: set, input_3: set) -> set:
    inputs = (
        input_1 or set(), 
        input_2 or set(),
        input_3 or set()
    )

    return set.union(*inputs)