scripts/relpath.sh

   1 #!/bin/sh
   2
   3 #   BSD LICENSE
   4 #
   5 #   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   6 #   All rights reserved.
   7 #
   8 #   Redistribution and use in source and binary forms, with or without
   9 #   modification, are permitted provided that the following conditions
  10 #   are met:
  11 #
  12 #     * Redistributions of source code must retain the above copyright
  13 #       notice, this list of conditions and the following disclaimer.
  14 #     * Redistributions in binary form must reproduce the above copyright
  15 #       notice, this list of conditions and the following disclaimer in
  16 #       the documentation and/or other materials provided with the
  17 #       distribution.
  18 #     * Neither the name of Intel Corporation nor the names of its
  19 #       contributors may be used to endorse or promote products derived
  20 #       from this software without specific prior written permission.
  21 #
  22 #   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23 #   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24 #   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25 #   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26 #   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27 #   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28 #   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29 #   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30 #   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31 #   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32 #   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33
  34 #
  35 # print the relative path of $1 from $2 directory
  36 # $1 and $2 MUST be absolute paths
  37 #
  38
  39 if [ $# -ne 2 ]; then
  40         echo "Bad arguments"
  41         echo "Usage:"
  42         echo "  $0 path1 path2"
  43         exit 1
  44 fi
  45
  46 REL1=${1#/}
  47 REL2=${2#/}
  48
  49 left1=${REL1%%/*}
  50 right1=${REL1#*/}
  51 prev_right1=$REL1
  52 prev_left1=
  53
  54 left2=${REL2%%/*}
  55 right2=${REL2#*/}
  56 prev_right2=$REL2
  57 prev_left2=
  58
  59 while [ "${right1}" != "" -a "${right2}" != "" ]; do
  60
  61         if [ "$left1" != "$left2" ]; then
  62                 break
  63         fi
  64
  65         prev_left1=$left1
  66         left1=$left1/${right1%%/*}
  67         prev_right1=$right1
  68         right1=${prev_right1#*/}
  69         if [ "$right1" = "$prev_right1" ]; then
  70                 right1=""
  71         fi
  72
  73         prev_left2=$left2
  74         left2=$left2/${right2%%/*}
  75         prev_right2=$right2
  76         right2=${prev_right2#*/}
  77         if [ "$right2" = "$prev_right2" ]; then
  78                 right2=""
  79         fi
  80 done
  81
  82 if [ "${left1}" != "${left2}" ]; then
  83         right2=${prev_right2}
  84         right1=${prev_right1}
  85 fi
  86
  87 while [ "${right2}" != "" ]; do
  88         prefix=${prefix}../
  89         prev_right2=$right2
  90         right2=${right2#*/}
  91         if [ "$right2" = "$prev_right2" ]; then
  92                 right2=""
  93         fi
  94 done
  95
  96 echo ${prefix}${right1}
  97
  98 exit 0