utils-dev/absolute.sh

   1 #!/bin/sh
   2 # ---------------------------------------------------------------------------
   3 # Multi-Phasic Applications: SquirrelJME
   4 #     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 #     Copyright (C) Multi-Phasic Applications <multiphasicapps.net>
   6 # ---------------------------------------------------------------------------
   7 # SquirrelJME is under the GNU General Public License v3, or later.
   8 # For more information see license.txt.
   9 # ---------------------------------------------------------------------------
  10 # DESCRIPTION: Calculates the absolute path of a file
  11
  12 # File to check
  13 __check="$1"
  14
  15 # path is absolute, just needs . and .. removed
  16 if echo "$__check" | grep '^\/' > /dev/null
  17 then
  18         __yuck="$__check"
  19
  20 # Get relative path from PWD
  21 else
  22         __yuck="$(pwd)/$__check"
  23 fi
  24
  25 # Split path by slashes and handle each line
  26 # Need file due to argument stuff.
  27 rm -f /tmp/$$.abs
  28 touch /tmp/$$.abs
  29 echo "$__yuck" | tr '/' '\n' | while read __seg
  30 do
  31         # If this segment is ".", ignore it
  32         # Also ignore blank segments too
  33         if [ "$__seg" = "." ] || [ -z "$__seg" ]
  34         then
  35                 continue
  36
  37         # If this is .., remove the topmost path element
  38         elif [ "$__seg" = ".." ]
  39         then
  40                 sed 's/\/[^/]*$//g' < /tmp/$$.abs > /tmp/$$.abs2
  41                 mv /tmp/$$.abs2 /tmp/$$.abs
  42
  43         # Otherwise append to path
  44         else
  45                 __part="$(cat "/tmp/$$.abs")"
  46                 printf '%s/%s' "$__part" "$__seg" > /tmp/$$.abs
  47         fi
  48 done
  49
  50 # Blank result ends in /
  51 __result="$(cat /tmp/$$.abs)"
  52 rm -f /tmp/$$.abs
  53 if [ -z "$__result" ]
  54 then
  55         echo "/"
  56 else
  57         echo "$__result"
  58 fi
  59