olemus
sisestatud käske loetlev käsk, näiteks Linuxis
=
a command used to view the previously executed commands

ülevaateid
https://en.wikipedia.org/wiki/History_(command)

http://www.tldp.org/LDP/GNU-Linux-Tools-Summary/html/x1712.htm

http://www.thegeekstuff.com/2008/08/15-examples-to-master-linux-command-line-history

https://www.computerhope.com/unix/uhistory.htm