Script that will do something when start computer

If you need to put some script that will do something when
start computers where installed Debian or one of clones (Ubuntu, Mint, sidux ..), for example
add the IP address, adding routes and start ssh server:

"
ifconfig 192.168.1.1 netmask 255.255.255.0 eth0 up
route add default gw 192.168.1.1
/etc/init.d/ssh start
"

this is all stored in a file like "/home/user/script"

then the file (as root) copy to the folder:

$ cp /home/user/script/etc/init.d/

and add right after the execution:

$ chmod +X /etc/init.d/script

After this, it is necessary to do the command:

$ update-rc.d script defaults

With this we add the script to start Debian.

If we want to delete from the start, do:

$ update-rc.d -f script remove

Shouldn't it be?

$ cp /home/user/script /etc/init.d/