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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Masahiro Yamada' <masahiroy@kernel.org>,
        "linux-kbuild@vger.kernel.org" <linux-kbuild@vger.kernel.org>
CC:     Dominique Martinet <asmadeus@codewreck.org>,
        Michal Marek <michal.lkml@markovi.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 3/3] kbuild: rewrite ld-version.sh in shell script
Thread-Topic: [PATCH 3/3] kbuild: rewrite ld-version.sh in shell script
Thread-Index: AQHW0KfRQeCeMjpix0eG5Uz36Tqg2qnz/UVA
Date:   Sat, 12 Dec 2020 21:47:40 +0000
Message-ID: <ff1adc79f7884ba1a1dcbdd806e81d7b@AcuMS.aculab.com>
References: <20201212165431.150750-1-masahiroy@kernel.org>
 <20201212165431.150750-3-masahiroy@kernel.org>
In-Reply-To: <20201212165431.150750-3-masahiroy@kernel.org>
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From: Masahiro Yamada
> Sent: 12 December 2020 16:55
> 
> This script was written in awk in spite of the file extension '.sh'.
> Rewrite it as a shell script.
...
> +#
> +# Usage: $ ./scripts/ld-version.sh ld
> +#
> +# Print the linker version of `ld' in a 5 or 6-digit form
> +# such as `23501' for GNU ld 2.35.1 etc.
> +
> +first_line="$($* --version | head -n 1)"
> +
> +if ! ( echo $first_line | grep -q "GNU ld"); then
> +	echo 0
> +	exit 1
> +fi
> +
> +# Distributions may append an extra string like 2.35-15.fc33
> +# Take the part that consists of numbers and dots.
> +VERSION=$(echo $first_line | sed 's/.* \([^ ]*\)$/\1/' | sed 's/^\(^[0-9.]*\).*/\1/')
> +MAJOR=$(echo $VERSION | cut -d . -f 1)
> +MINOR=$(echo $VERSION | cut -d . -f 2)
> +PATCHLEVEL=$(echo $VERSION | cut -d . -f 3)
> +printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL


Hmmmm.....
You've managed to convert an awk script into something that requires
sh, head, grep, sed (twice), and cut (thrice).
Plus (probably) a few sub-shells.

It is quite ease to do it all in all in the shell.

	David

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