ac_flag, the AFORK flag is turned on by each
and turned off by an
ac_comm member is inherited from the parent process and
is reset by any call to
Each time the system charges the process with a clock tick,
it also adds the current process size
ac_mem member, computed as follows:
(data size) + (text size) / (number of in-core processes using text)
The value of
can be viewed as an approximation to the
mean process size, as modified by text-sharing.
ac_memvalue for a short-lived command gives little information about the actual size of the command, because
ac_memmay be incremented while a different command (for example, the shell) is being executed by the process.
X/Open Portability Guide, Issue 3, 1989 .