Re: [PATCH v2 1/2] common/rc: add _parse_size_string

Long An
2022-06-17T06:45:11Z

On Thu, 2022-06-16 at 11:25 -0400, Gabriel Krisman Bertazi wrote:
> An Long <lan@suse.com> writes:
>
> > + if [[ $str =~ ^[0-9]+[a-zA-Z]$ ]] ; then
> > + size=${str:: -1}
> > + endchar=${str: -1}
> > + case $endchar in
> > + e|E)
> > + mult=$((mult * 1024))
> > + ;&
> > + p|P)
> > + mult=$((mult * 1024))
> > + ;&
> > + t|T)
> > + mult=$((mult * 1024))
> > + ;&
> > + g|G)
> > + mult=$((mult * 1024))
> > + ;&
> > + m|M)
> > + mult=$((mult * 1024))
> > + ;&
> > + k|K)
> > + mult=$((mult * 1024))
> > + ;&
> > + b|B)
> > + ;;
> > + *)
> > + echo "unknown size descriptor
> > $endchar"
> > + exit 1
> > + esac
> > + elif [[ $str =~ ^[0-9]+$ ]] ; then
> > + size=$str
> > + else
> > + echo "size value $str is invalid"
> > + exit 1
> > + fi
> > +
> > + size=$((size * mult))
> > + echo $size
> > +}
>
> Hi An,
>
> Coreutils has numfmt(1) to do this kind of conversion. I wonder if
> we
> could use it here, unless it is not available all the platforms that
> matters for xfstests, though:
>
> $ echo 1K | numfmt --from=iec
> 1024
>

Hi Gabriel,

Using numfmt should reduce the code. But it brings new problems：

1) numfmt doesn't support lowercase
echo 4k | numfmt --from=iec
numfmt: invalid suffix in input: '4k'

2) This cannot clearly point out the error

3) Value range is limited
echo 16E | numfmt --from=iec
numfmt: value too large to be printed: '1.84467e+19' (consider using --
to)

4) Added system dependencies

More code is required to solve above problems, and not elegant.

> > +
> > # Create fs of certain size on scratch device
> > # _scratch_mkfs_sized <size in bytes> [optional blocksize]
> > _scratch_mkfs_sized()
--
An Long <lan@suse.com>
SUSE QE LSG, QE 2, Beijing