Add or remove a script on startup in Debian or Ubuntu

Add a script:

1. put the script under /etc/init.d/
2. #chmod 755 myscript
3. #update-rc.d myscript defaults
4. #reboot

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Remove :

1. #cd /etc/init.d/
2. #update-rc.d -f myscript remove
3. #reboot

more over , please use "man update-rc.d" command