[c0l0]

Linux disagrees; try

    strings /proc/*/environ

to see for yourself.

On Solaris/SunOS, you could use `pargs -e $PID`. And so on.

Having separate UIDs to run your processes A and B under shields either one from peeking at the other's environment, though. UNIX DAC is simple and powerful enough for MOST security concerns, I would argue.