Howto add autostartup applications

[Johan <johansche@telkomsa.net>]

Good day,

On the internet I was informed to use update-rc.d.

According the man page..:
EXAMPLES
      Insert links using the defaults:
         update-rc.d foobar defaults

This is what I get..:

unknown001e33032a68:/home/johan# whereis gkrellm
gkrellm: /usr/bin/gkrellm /usr/share/man/man1/gkrellm.1.gz

unknown001e33032a68:/home/johan# update-rc.d /usr/bin/gkrellm defaults
update-rc.d: /etc/init.d//usr/bin/gkrellm: file does not exist

unknown001e33032a68:/home/johan#  update-rc.d gkrellm defaults
update-rc.d: /etc/init.d/gkrellm: file does not exist

unknown001e33032a68:/home/johan#

Please what is wrong.
Thanks
Johan