What happens if printf is not handled

Question

I'm current supporting some legacy software written aeon ago, compiled in gcc 2.95.3. The program is ran in an SBC, occasionally I had to telnet into it to fix things. I notice that when the SBC is running on its own, it display some unexpected behavior eg missed executions.

When I do telnet in, slay the process and execute it manually, it stays fine that way. I'm suspecting that this has to do with performing printf without a proper terminal/console for it to print on.

If printf are not handled, what would be the effect of it?

Answer 1

可能是系统正在尝试打印到硬件串行端口（这确实很慢），并且当您使用TCP端口代替telnet时，才打印？

Answer 2

It depends on the stdio library you use, most will attempt to write to console anyway, so...

You should redirecting your STDOUT and STDERR to NULL or to a file, this should be quiet easy. gcc 2.95 was very stable so we can pretty much rule out any problems there.