Messages in this thread | | | From | Masahiro Yamada <> | Date | Wed, 14 Sep 2022 22:00:50 +0900 | Subject | Re: [PATCH 05/15] kbuild: build init/built-in.a just once |
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On Wed, Sep 14, 2022 at 6:46 PM David Laight <David.Laight@aculab.com> wrote: > > ... > > > +VERSION=$(cat .version) 2>/dev/null && > > > +VERSION=$(expr $VERSION + 1) 2>/dev/null || > > > +VERSION=1 > > What's wrong with: > VERSION=$(($(cat .version 2>/dev/null) + 1))
One reason was, the original code used 'expr'.
> If you are worried about .version not containing a valid > number and $((...)) failing then use ${VERSION:-1} later.
Maybe another reason is, I want to make the behavior deterministic when the .version file contains a non-integer string.
$ unset FOO $ echo FOO > .version $ echo $(($(cat .version 2>/dev/null) + 1)) 1
$ export FOO=100 $ echo FOO > .version $ echo $(($(cat .version 2>/dev/null) + 1)) 101
I want the script to consistently return 1 whether or not 'FOO' is available in the user's environment.
> David > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) >
-- Best Regards Masahiro Yamada
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