self int indent;

perlxs*:::sub-entry
/strstr(copyinstr(arg1), "Mungo") != 0/
{
    printf("%*s%s %s %s:%d\n", self->indent, " ",
           probename == "sub-entry" ? "->" : "<-",
           copyinstr(arg0), copyinstr(arg1), arg2);
    self->indent++;
}
perlxs*:::sub-return
/strstr(copyinstr(arg1), "Mungo") != 0/
{
    self->indent--;
    printf("%*s%s %s %s:%d\n", self->indent, " ",
           probename == "sub-entry" ? "->" : "<-",
           copyinstr(arg0), copyinstr(arg1), arg2);
}