Re: [ptxdist] [PATCH] ptxdist: Check for GNU readlink

[Michael Olbrich <m.olbrich@pengutronix.de>]

On Tue, Feb 14, 2012 at 09:55:47PM +0100, Bernhard Walle wrote:
> ptxdist heavily uses "readlink -f" which only works with GNU readlink.
> So add the usual check here.
> 
> However, because "readlink -f" is also used before the symlinks in the
> ptxdist directory is added to the PATH, that "readlink -f" call is
> replaced by a bash-only implementation. This one is copied from
> http://mailman.archlinux.org/pipermail/pacman-dev/2009-February/008130.html.
> 
> Tested on Mac OS 10.7.
> 
> Signed-off-by: Bernhard Walle <bernhard@bwalle.de>
> ---
>  Makefile.in  |    1 +
>  bin/ptxdist  |   25 ++++++++++++++++++++++++-
>  configure.ac |    1 +
>  3 files changed, 26 insertions(+), 1 deletions(-)
> 
> diff --git a/Makefile.in b/Makefile.in
> index e8544d1..2181608 100644
> --- a/Makefile.in
> +++ b/Makefile.in
> @@ -55,6 +55,7 @@ environment:
>  	@ln -sf @PYTHON@ "$(abs_srcdir)/bin/python"
>  	@ln -sf @SED@ "$(abs_srcdir)/bin/sed"
>  	@ln -sf @TAR@ "$(abs_srcdir)/bin/tar"
> +	@ln -sf @READLINK@ "$(abs_srcdir)/bin/readlink"
>  	@echo " done"
>  
>  clean:
> diff --git a/bin/ptxdist b/bin/ptxdist
> index eb3366a..9355b1f 100755
> --- a/bin/ptxdist
> +++ b/bin/ptxdist
> @@ -1843,6 +1843,29 @@ EOF
>  ################ setup stuff only ################################
>  ##################################################################
>  
> +#
> +# bash implementation of realpath / readlink -f
> +#   arg1 - filename
> +realpath()
> +{
> +	local fname oldfname
> +

hmmm, scary.

> +	fname=${1%/} # strips trailing '/'
> +	while [ -L "$fname" ]; do

we prefer "${fname}" in ptxdist. Please change this everywhere.

> +		oldfname="$fname"
> +		fname="$(command ls -l $fname)"

fname="$(command ls -l "${fname}")"

> +		fname="${fname#*\> }"

hmmm, "${fname#*\ -> }" is better? Or is the output different for other
'ls' implementations?
Another idea: Is the problem that "readlink -f" does not work or does
"readlink" not exist at all? Any readlink implementations should work here
for fname="$(readlink "${fname}")".

> +		if [ "$fname" = . ] ; then
> +			fname="$(dirname $oldfname)"
> +		elif echo $fname | grep -vq '^/' - ; then

		elif [ "${fname}" -eq "${fname#/}" ]; then

> +			fname="$(dirname $oldfname)/$fname"

			fname="$(dirname "${oldfname}")/${fname}"

> +		fi
> +	done
> +	pushd $(dirname $fname) > /dev/null

	( cd "$(dirname "${fname}")"

> +	fname=$(pwd -P)/$(basename $fname)

	)

Michael

> +	popd > /dev/null
> +	echo $fname
> +}
>  
>  #
>  # figure out PTXDIST_TOPDIR
> @@ -1859,7 +1882,7 @@ EOF
>  setup_topdir() {
>  	local ptxdist topdir
>  
> -	ptxdist="$(readlink -f "${0}")" &&
> +	ptxdist="$(realpath "${0}")" &&
>  	topdir="$(cd "$(dirname "${ptxdist}")"/.. && pwd)" || return
>  
>  	#
> diff --git a/configure.ac b/configure.ac
> index 00c2521..497441c 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -152,6 +152,7 @@ GNU_COREUTILS(md5sum)
>  GNU_COREUTILS(mkdir)
>  GNU_COREUTILS(install)
>  GNU_COREUTILS(stat)
> +GNU_COREUTILS(readlink)
>  
>  dnl Check for egrep
>  AC_PROG_EGREP
> -- 
> 1.7.9
> 
> 
> -- 
> ptxdist mailing list
> ptxdist@pengutronix.de
> 

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