Subject: Re: [PATCH] Remove perl dependency from git-submodule.sh

From: Johannes Sixt <[email-masked]>
Date: Thu, 31 May 2012 11:19:04 +0200

Am 5/31/2012 10:48, schrieb Fredrik Gustafsson:
> Rewrote a perl section in sh.

> The code may be a bit slower (doing grep on strings instead of using
> perl-lists).

"A lot" would be more correct on Windows :-) But it can be avoided, I think.

>  module_list()
>  {
> +	unmerged=
> +	null_sha1=0000000000000000000000000000000000000000
>  	git ls-files --error-unmatch --stage -- "$@" |
> -	perl -e '
> -	my %unmerged = ();
> -	my ($null_sha1) = ("0" x 40);
> -	while (<STDIN>) {
> -		chomp;
> -		my ($mode, $sha1, $stage, $path) =
> -			/^([0-7]+) ([0-9a-f]{40}) ([0-3])\t(.*)$/;
> -		next unless $mode eq "160000";
> -		if ($stage ne "0") {
> -			if (!$unmerged{$path}++) {
> -				print "$mode $null_sha1 U\t$path\n";
> -			}
> -			next;
> -		}
> -		print "$_\n";
> -	}
> -	'
> +	while read mode sha1 stage path

Be prepared for backslashes in the path name:

	while read -r mode sha1 stage path

> +	do
> +		if test $mode -eq 160000

$mode is not a number, but a string: test "$mode" = 160000

> +		then
> +			if test $stage -ne 0

That $stage looks like a number is of no importance, either.

> +			then
> +				if test -z "$(echo $unmerged | grep "|$path|")"
> +					then
> +					echo "$mode $null_sha1 U\t$path"
> +				fi
> +				unmerged="$unmerged|$path|"

IIUC, the purpose of $unmerged and this check is to avoid that an unmerged
path is dumped for each stage that is listed by ls-files. Therefore it
should be sufficient to just check that the current path is different from
the last path.

> +			else
> +				echo "$mode $sha1 $stage\t$path"
> +			fi
> +		fi
> +	done
>  }
>  
>  #

-- Hannes