[arch-projects] [RFC] Remove cut, grep and sed from mdadm initcpio hook

[Gerardo Exequiel Pozzi]

On 11/16/2011 03:34 AM, Gerardo Exequiel Pozzi wrote:
> https://gist.github.com/1369428 (this patch)
> https://gist.github.com/1369424 (standalone test script)
>
> --- /lib/initcpio/hooks/mdadm    2011-09-14 04:10:48.000000000 -0300
> +++ hooks/mdadm    2011-11-16 03:32:30.064535002 -0300
> @@ -6,7 +6,7 @@
>      # for partitionable raid, we need to load md_mod first!
>      modprobe md_mod 2>/dev/null
>      # If md is specified on commandline, create config file from 
> those parameters.
> -    if [ "$(echo $input | grep "md=")" ]; then
> +    if [ -n "${md}" ]; then
>          #Create initial mdadm.conf
>          # scan all devices in /proc/partitions
>          echo DEVICE partitions > $mdconfig
> @@ -14,26 +14,30 @@
>              case $i in
>                  # raid
>                  md=[0-9]*,/*)
> -                    device="$(echo "$i" | sed -e 's|,/.*||g' -e 
> 's|=||g')"
> -                    array="$(echo $i | cut -d, -f2-)"
> +                    device="${i%%,*}"
> +                    device="${device/=/}"
> +                    array="${i#*,}"
>                      echo "ARRAY /dev/$device devices=$array" >> 
> $mdconfig
>                      ;;
>                  # partitionable raid
>                  md=d[0-9]*,/*)
> -                    device="$(echo "$i" | sed -e 's|,/.*||g' -e 
> 's|=|_|g')"
> -                    array="$(echo $i | cut -d, -f2-)"
> +                    device="${i%%,*}"
> +                    device="${device/=/_}"
> +                    array="${i#*,}"
>                      echo "ARRAY /dev/$device devices=$array" >> 
> $mdconfig
>                      ;;
>                  # raid UUID
> -                md=[0-9]*,[0-9,a-z]*)
> -                    device="$(echo "$i" | sed -e 's|,.*||g' -e 
> 's|=||g')"
> -                    array="$(echo $i | cut -d, -f2-)"
> +                md=[0-9]*,[0-9,a-f]*)
> +                    device="${i%%,*}"
> +                    device="${device/=/}"
> +                    array="${i#*,}"
>                      echo "ARRAY /dev/$device UUID=$array" >> $mdconfig
>                      ;;
>                  # partitionable raid UUID
> -                md=d[0-9]*,[0-9,a-z]*)
> -                    device="$(echo "$i" | sed -e 's|,.*||g' -e 
> 's|=|_|g')"
> -                    array="$(echo $i | cut -d, -f2-)"
> +                md=d[0-9]*,[0-9,a-f]*)
> +                    device="${i%%,*}"
> +                    device="${device/=/_}"
> +                    array="${i#*,}"
>                      echo "ARRAY /dev/$device UUID=$array" >> $mdconfig
>                      ;;
>              esac
>
>

I guess that this code can be simplified a bit, does not make sense 
today differentiate between non-partitioned and partitioned md devs. 
 From mdadm(8) manpage:

"From  kernel version, 2.6.28 the "non-partitioned array" can actually 
be partitioned.  So the "md_dNN" names are no longer needed, and 
partitions such as "/dev/mdNNpXX" are possible."

Maybe we can add some note if user wants the legacy name.



-- 
Gerardo Exequiel Pozzi
\cos^2\alpha + \sin^2\alpha = 1