[Extracted, edited down, and expanded from a mailing list post.]
dpkg:
p@satan$ dpkg -S hostname.sh
sysvinit: /etc/init.d/hostname.sh
RM notes: Works only if the package is installed.
auto-apt:
p@satan$ auto-apt search
hostname.sh
etc/init.d/hostname.sh base/sysvinit
Even better: When building software in the environment entered by typing "auto-apt run", auto-apt will detect your need for a file not yet installed, and initiate an apt-get fetch of the package on your behalf.
apt-file:
satan# apt-file search hostname.sh
sysvinit: etc/init.d/hostname.sh
Local package listing for sysvinit:
p@satan$ dpkg -L sysvinit | grep hostname
/etc/init.d/hostname.sh
In fact, there's no package on my system named initscripts:
satan# dpkg -l "initscr*"
No packages found matching initscr*.
The package listing on the Debian website shows hostname.sh to be in sysvinit: