> I believe that modern Linux and FreeBSD implementations use 32 bit
> ints for the pid_t.
> There will never be that many processes on a 32 bit
> OS, but since they just go forward until they wrap, getting a pid bigger
> than 16 bits is probably even to be expected.
However, they don't plainly wrap. There is a system limit in the kernel,
controlled via "/proc/sys/kernel/pid_max".
Even on 64-bit machines (where pid_t is also an 'int', i.e. a 64-bit
number), PIDs don't get up to such huge numbers.