* ps / -A / fax / auxww
* top / htop / atop 2
* pgrep -x
* pstree -p (parent/child/fork)
* background/forground:  & ctrl-z jobs bg fg
* kill -KILL / killall / man signal / SIGTERM , SIGKILL , SIGHUP, SIGINT
* lsof -n / list open files
* /proc , cmdline , cwd , exe , loginuid , fd , environ
       cat /proc/uptime
       cat /proc/version
       cat /proc/swaps
       cat /proc/partitions
       cat /proc/cpuinfo
* ps -p 1 -o comm=