buildtools/relpath.sh

   1 #!/bin/sh
   2 # SPDX-License-Identifier: BSD-3-Clause
   3 # Copyright(c) 2010-2014 Intel Corporation
   4
   5 #
   6 # print the relative path of $1 from $2 directory
   7 # $1 and $2 MUST be absolute paths
   8 #
   9
  10 if [ $# -ne 2 ]; then
  11         echo "Bad arguments"
  12         echo "Usage:"
  13         echo "  $0 path1 path2"
  14         exit 1
  15 fi
  16
  17 # get the real absolute path, derefencing symlinks
  18 ABS1="$(dirname $(readlink -f $1))/$(basename $1)"
  19 ABS2=$(readlink -f $2)
  20
  21 # remove leading slash
  22 REL1=${ABS1#/}
  23 REL2=${ABS2#/}
  24
  25 left1=${REL1%%/*}
  26 right1=${REL1#*/}
  27 prev_right1=$REL1
  28 prev_left1=
  29
  30 left2=${REL2%%/*}
  31 right2=${REL2#*/}
  32 prev_right2=$REL2
  33 prev_left2=
  34
  35 prefix=
  36
  37 while [ "${right1}" != "" -a "${right2}" != "" ]; do
  38
  39         if [ "$left1" != "$left2" ]; then
  40                 break
  41         fi
  42
  43         prev_left1=$left1
  44         left1=$left1/${right1%%/*}
  45         prev_right1=$right1
  46         right1=${prev_right1#*/}
  47         if [ "$right1" = "$prev_right1" ]; then
  48                 right1=""
  49         fi
  50
  51         prev_left2=$left2
  52         left2=$left2/${right2%%/*}
  53         prev_right2=$right2
  54         right2=${prev_right2#*/}
  55         if [ "$right2" = "$prev_right2" ]; then
  56                 right2=""
  57         fi
  58 done
  59
  60 if [ "${left1}" != "${left2}" ]; then
  61         right2=${prev_right2}
  62         right1=${prev_right1}
  63 fi
  64
  65 while [ "${right2}" != "" ]; do
  66         prefix=${prefix}../
  67         prev_right2=$right2
  68         right2=${right2#*/}
  69         if [ "$right2" = "$prev_right2" ]; then
  70                 right2=""
  71         fi
  72 done
  73
  74 echo ${prefix}${right1}
  75
  76 exit 0