buildtool/linux/tools/x86_64-linux-gnu/sysroot/usr/lib/systemd/systemd-sysv-install

#!/bin/sh
# This script is called by "systemctl enable/disable" when the given unit is a
# SysV init.d script. It needs to call the distribution's mechanism for
# enabling/disabling those, such as chkconfig, update-rc.d, or similar. This
# can optionally take a --root argument for enabling a SysV init script
# in a chroot or similar.
set -eu

usage() {
    echo "Usage: $0 [--root=path] enable|disable|is-enabled <sysv script name>" >&2
    exit 1
}

ROOT=

# parse options
eval set -- "$(getopt -o r: --long root: -- "$@")"
while true; do
    case "$1" in
        -r|--root)
            ROOT="$2"
            shift 2 ;;
        --) shift ; break ;;
        *) usage ;;
    esac
done

NAME="${2:-}"

run() {
    if [ -n "$ROOT" ] && [ "$ROOT" != "/" ]; then
        _SKIP_SYSTEMD_NATIVE=1 chroot "$ROOT" /usr/sbin/update-rc.d "$@"
    else
        _SKIP_SYSTEMD_NATIVE=1 /usr/sbin/update-rc.d "$@"
    fi
}

[ -n "$NAME" ] || usage

case "$1" in
    enable)
        # call the command to enable SysV init script $NAME here..
        run "$NAME" defaults
        run "$NAME" enable
        ;;
    disable)
        run "$NAME" defaults
        run "$NAME" disable
        ;;
    is-enabled)
        # exit with 0 if $NAME is enabled, non-zero if it is disabled
        ls "$ROOT"/etc/rc[S5].d/S??"$NAME" >/dev/null 2>&1
        ;;
    *)
        usage ;;
esac