extra/scripts/relative_path.sh

   1 #! /bin/sh
   2 #
   3 # Copyright 2003 Alexandre Oliva <aoliva@redhat.com>
   4 # Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
   5 #
   6 # Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   7 #
   8
   9 # This script computes a relative pathname from $1 to $2
  10 # They are assumed to not contain . or .. pathname components,
  11 # but if both directories exist and cd/pwd canonicalizes pathnames,
  12 # this shouldn't matter.  PWD_CMD may be set to some pwd command that does.
  13
  14 from=`(cd $1 > /dev/null && ${PWD_CMD-pwd} || echo $1) 2>/dev/null | sed 's,//*,/,g;s,/*$,,'`
  15 target=`(cd $2 > /dev/null && ${PWD_CMD-pwd} || echo $2) 2>/dev/null | sed 's,//*,/,g;s,/*$,,'`
  16
  17 case $from in /* | "") ;; *) from=`${PWD_CMD-pwd}`/$from ;; esac
  18 case $target in /* | "") ;; *) target=`${PWD_CMD-pwd}`/$target ;; esac
  19
  20 case $target in
  21 "$from" | "$from/"*)
  22   dots=`echo $from | sed s,.,.,g`
  23   echo $target | sed "s,^$dots/*,,;s,[^/]$,&/,"
  24   exit 0
  25   ;;
  26 esac
  27
  28 case $from in
  29 "$target/"*)
  30   dots=`echo $target | sed s,.,.,g`
  31   echo $from/ | sed "s,^$dots/*,,;s,[^/]$,&/,;s,[^/]*/*,../,g;s,[^/]$,&/,"
  32   exit 0
  33   ;;
  34 esac
  35
  36 # Without trailing slash, from=/usr/lib and target=/uclibc/lib
  37 # mistakenly concludes that prefix=/u
  38 #prefix=`echo $from///$target | sed 's,\(\(/[^/]*\)*\).*///\1.*,\1,'`
  39 prefix=`echo $from///$target | sed 's,\(\(/[^/]*\)*/\).*///\1.*,\1,'`
  40 dots=`echo $prefix | sed s,.,.,g`
  41 from=`echo $from | sed "s,^$dots,,"`
  42 target=`echo $target | sed "s,^$dots,,"`
  43
  44 from=`echo $from | sed 's,[^/][^/]*,..,g;s,.$,&/,'`
  45 echo ${from}$target/
  46
  47 exit 0