Besides the raw or direct format via /proc/PID/maps (which we saw how to interpret in the previous section), there are some wrapper utilities that help us more easily interpret the user-mode VAS. Among them are the additional (raw) /proc/PID/smaps pseudo-file, the pmap(1) and smem(8) utilities, and my own simple utility (christened procmap).
The kernel provides detailed information on each segment or mapping via the /proc/PID/smaps pseudo-file under proc. Do try cat /proc/self/smaps to see this for yourself. You will notice that for each segment (mapping), a good amount of detail information is provided on it. The man page on proc(5) helps explain the many fields seen.
For both the pmap(1) and smem(8) utilities, I refer you to the man pages on them for details. For example, with pmap(1), the man page informs us of the more verbose -X and -XX options:
-X Show even...