[pacman-dev] [PATCH] repo-add: added a realpath implementation in bash

[Allan McRae]

Yun Zheng Hu wrote:
> When realpath or readlink is not available it will fallback to a
> realpath implementation in bash. An extra check is also added for
> "readlink -f", because not all platforms support the -f flag.
>
> The readlink implementation in bash is borrowed from Debian's dpkg tools.
>
> Signed-off-by: Yun Zheng Hu <yunzheng.hu at gmail.com>
> ---
>  scripts/repo-add.sh.in |   23 ++++++++++++++++++++---
>  1 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/repo-add.sh.in b/scripts/repo-add.sh.in
> index c89e2a5..ea16731 100644
> --- a/scripts/repo-add.sh.in
> +++ b/scripts/repo-add.sh.in
> @@ -297,11 +297,28 @@ fi
>  # check for and store the name of a realpath-like program
>  if [ $(type -t realpath) ]; then
>  	realpath='realpath'
> -elif [ $(type -t readlink) ]; then
> +elif [ $(type -t readlink) -a "$(readlink -f . 2>/dev/null)" != "" ]; then
>  	realpath='readlink -f'
>  else
> -	error "$(gettext "Either realpath or readlink are required by repo-add.")"
> -	exit 1 # $E_MISSING_PROGRAM
> +	realpath_bash()
> +	{
> +		fname=${1%/} # strips trailing '/'
> +		while [ -L "$fname" ]; do
> +			oldfname="$fname"
> +			fname="$(command ls -l $fname)"
> +			fname="${fname#*\> }"
> +			if [ "$fname" = . ] ; then
> +				fname="$(dirname $oldfname)"
> +			elif echo $fname | grep -vq '^/' - ; then
> +				fname="$(dirname $oldfname)/$fname"
> +			fi
> +		done
> +		pushd $(dirname $fname) > /dev/null
> +		fname=$(pwd -P)/$(basename $fname)
> +		popd > /dev/null
> +		echo $fname
> +	}
> +	realpath=realpath_bash
>  fi
>
>  # main routine
>   


I haven't looked at this in detail yet, but if this solution is more 
portable and has no feature loss, why not use it by default?

Allan