How do you replace terminal text without the cursor jumping around?

[versed meadow]

code with the jumping cursor:

        while (true) {
            try writer.print("\r{any}", .{milliTimestamp()});
        }

[median geode]

write into a buffer and then use writer.writeAll to push that all to stdout at the same time (or use a buffered writer and flush at the end of each iteration)