type file;

file cs <"cs.sh">;

app (file [] _fs) createfs (file _cFsScript)
{
    sh @_cFsScript;
}

(string s_obj) sum_obj (file _cs)
{
    string [] s;
    iterate i {
        s[i] = @strcat("upf_",i,".txt");
    } until (i == 3);
    
    file fs[] <array_mapper; files=s>; # doesn't work, just hangs
#    file fs[] <fixed_array_mapper; files="upf_0.txt, upf_1.txt, upf_2.txt">; # works
    fs = createfs(_cs);
    
    s_obj = readData(fs[0]);
}

tracef("\n*** Ready to call sum_obj\n\n");
string result = sum_obj(cs);
tracef("\n*** Script parameters: result=%s\n\n", result);