setproctitle() is only for the current process. It is a system-specific interface implemented in libc (in OpenBSD&#x2F;FreeBSD a sysctl() to set the memory address where the string is stored).<p>ps(1) examines other processes and again uses a system-specific interface to the kernel to retrieve all information about other processes (using kvm(3) on OpenBSD&#x2F;FreeBSD).