What is the proper equivalent of "while(true)" in plain C?

Question

Since C doesn't have bools, what is the proper variable to put in place of true in an algorithm that uses

do
{
   // ... 
} while(true);

???

Should a proper C programmer do

do
{
   // ... 
} while(1);

or is there a specific variable reserved to mean "something that is not zero/NULL" ?

Answer 1

Usually nowadays I see

while(1) {
    ...
}

It used to be common to see

for(;;) {
    ...
}

It all gets the point across.