Collect information about present multipath devices in sufficient for `awk` format

mpath-debug.sh

#!/usr/bin/env bash

# vim: set number tabstop=4 shiftwidth=4 smarttab expandtab:

_transform_slaves() {
    xargs -n1 -I{} realpath "/sys/block/{}/../../" | sort -u | tr '\n' ','
}

iterate_dms() {
    local dmname dmuuid dmslaves dmslavescnt

    for dmpath in /sys/block/dm-*; do
        dmname=$(grep '^mpath*' "$dmpath/dm/name")
        [ -z "$dmname" ] && continue;
        dmuuid=$(cat "$dmpath/dm/uuid")
        dmslaves=$(ls -1 "$dmpath/slaves")
        dmslavescnt=$(echo "$dmslaves" | wc -l)
        echo "$dmuuid $dmname $dmslavescnt $(echo "$dmslaves" | _transform_slaves)"
    done
}

iterate_dms