#!/bin/sh -e
#
# based on previous work by other people, modified by:
# 2020 Dennis Camera <dennis.camera at ssrq-sds-fds.ch>
#
# This file is part of cdist.
#
# cdist is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# cdist is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with cdist. If not, see <http://www.gnu.org/licenses/>.
#
# Finds disks of the system (excl. ram disks, floppy, cdrom)

uname_s="$(uname -s)"

case $uname_s in
    FreeBSD)
        sysctl -n kern.disks
    ;;
    OpenBSD)
        sysctl -n hw.disknames | grep -Eo '[lsw]d[0-9]+'
    ;;
    NetBSD)
        PATH=$(getconf PATH)
        sysctl -n hw.disknames | awk -v RS=' ' '/^[lsw]d[0-9]+/'
    ;;
    Linux)
        # list of major device numbers toexclude:
        #  ram disks, floppies, cdroms
        # https://www.kernel.org/doc/Documentation/admin-guide/devices.txt
        ign_majors='1 2 11'

        if command -v lsblk >/dev/null 2>&1
        then
            lsblk -e "$(echo "$ign_majors" | tr ' ' ',')" -dno name
        elif test -d /sys/block/
        then
            # shellcheck disable=SC2012
            ls -1 /sys/block/ \
            | awk -v ign_majors="$(echo "$ign_majors" | tr ' ' '|')" '
                {
                  devfile = "/sys/block/" $0 "/dev"
                  getline devno < devfile
                  close(devfile)
                  if (devno !~ "^(" ign_majors "):") print
                }'
        else
            echo "Don't know how to list disks on Linux without lsblk and sysfs." >&2
            echo 'If you can, please submit a patch.'>&2
        fi
    ;;
    *)
        printf "Don't know how to list disks for %s operating system.\n" "${uname_s}" >&2
        printf 'If you can please submit a patch\n' >&2
    ;;
esac \
| xargs