Removing initial zero from variables

[Johnny Rosenberg]

Den 18 februari 2012 19:54 skrev Johnny Rosenberg <gurus.knugum at gmail.com>:
> Here's yet another bash question, I know I asked quite a few lately:
>
> I have a little problem regarding arithmetic expressions in bash.
>
> I have a variable that contains a two digit number, for example 54 or
> 03. I want to use this variable in an arithmetic expression, something
> like:
> x=$((100*MyVar/MaxValue))
> The problem ocurs when MyVar is less than 10, because 03, for example,
> is considered an octal number. That works fine anyway in most cases,
> but 08 and 09 does not, of course.
>
> So I need some way to filter those initial zeroes out from MyVar:
> 01 → 1
> 02 → 2
> and so on.
> x=$(echo 08 | sed 's/^0*\([^0]*\)/\1/')
> echo $x
> 8
> So far, so good.
>
> However, 00 → 0 seems to be a problem:
> x=$(echo 00 | sed 's/^0*\([^0]*\)/\1/')
> echo $x
>
> (x is an empty string).
>
> Maybe sed isn't the best tool for this, but what is? Is there a ”trim
> number from inital zeroes” function available, perhaps?
>
>
> Kind regards
>
> Johnny Rosenberg
> ジョニー・ローゼンバーグ

Found it, I think:
$ echo 00 | bc
0
$ echo 000008 | bc
8
$

I'm not sure if there are any drawbacks yet, though…


Kind regards

Johnny Rosenberg
ジョニー・ローゼンバーグ