Re: [patch] scripts: clean-whitespace.sh

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 8 Jun 2007 08:40:42 +0200 Oleg Verych <olecom@flower.upol.cz> wrote:

> After running this script with filename as parameter,
> look (with diff) for, what can be corrected.

Sorry, but "run it and see what it did" is pretty poor documentation.

> Only "*.diff" and "*.patch" files are handled as patches.
> 
> Signed-off-by: Oleg Verych <olecom@flower.upol.cz>
> --
>  Two clean rules added, that can change look of damaged lines.
>  Yet script still fits one ordinary screen, so read the code!
> 
>  test cases: include/linux/ipv6.h, arch/x86_64/lib/{copy_user, memcpy}.S
> 
>  It's like lguest -- just for fun.
> 
>  clean-whitespace.sh |   28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
> 
> --- /dev/null	2007-04-04 10:55:19.204075250 +0200
> +++ linux-just-for-fun/scripts/clean-whitespace.sh	2007-06-08 07:53:21.000000000 +0200
> @@ -0,0 +1,28 @@
> +#!/bin/sh -e
> +# clean whitespace damage; i/o = $1/$1.clean
> +
> +IFS='' ; t="`printf '\t'`" ; s=' ' ; s4="$s$s$s$s" ; w79=79 ;
> +i="$1" ; o="$1.clean"
> +strip_file_end='/^$/{N;s_^\n$_&_;T e;:n;N;s_^.*\n\n$_&_;t n;:e;};'
> +not_patch_line='/^+[^+]/'
> +
> +case $1 in *[.]diff | *[.]patch)
> +	file=patch ; sp='+[!+]' ; p='+' ; addr="$not_patch_line";;
> +esac
> +
> +sed -n "${addr:-$strip_file_end} {
> +s|[$t$s]*$||;	# trailing whitespace
> +:next;		# x*8 spaces on the line start -> x*tabs
> +s|^\([\n]*\)$p\($t*\)$s4$s4|\1$p\2$t|;t next;	# \n is needed after N command
> +s|^\([\n]*\)$p\($t*\)$s*$t|\1$p\2$t|g;		# strip spaces between tabs
> +s|$s4$s4$s$s*|$t$t|g				# more than 8 spaces -> 2 tabs
> +s|$s*$t|$t|g	# strip spaces before tab; tradeoff: may break some alignment !
> +};p" -- "$i" >"$o" && echo "
> +please, see clean ${file:=source} file: $o
> +"
> +exec expand $i | while read -r line # check for long line
> +do   [ ${#line} -gt $w79 ] && case "$line" in $sp*) echo \
> +"at least one line wider than $w79 chars, found
> +check your $file, please
> +" 1>&2 ; exit ;; esac
> +done

Then again, it's a better strategy than trying to read the code ;)

Please, tell us what it does, so that we can decide whether we want it in
Linux.