rellns-sh

   1 #! /bin/sh
   2 # rellns-sh - Simplified ln program to generate relative symbolic link.
   3 # Copyright (C) 1996 Free Software Foundation, Inc.
   4 # Written by Ulrich Drepper <drepper@cygnus.com>, October 1996
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2, or (at your option)
   9 # any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19
  20 if test $# -ne 2; then
  21   echo "Usage: rellns SOURCE DEST" >&2
  22   exit 1
  23 fi
  24
  25 # We only handle the case where SOURCE is the name of an existing file
  26 if test ! -f $1; then
  27   echo "rellns: $1 must name an existing file" >&2
  28   exit 1
  29 fi
  30
  31 case $1 in
  32 /*)
  33   # Make both paths absolute.
  34   to=`echo $1 | sed 's%^/%%'`
  35
  36   if test -d $2; then
  37     from=`echo $2 | sed 's%/*$%%'`
  38   else
  39     from=`echo $2 | sed 's%/*[^/]*$%%'`
  40   fi
  41
  42   case "$from" in
  43   /*) from=`echo $from | sed 's%^/*%%'` ;;
  44   ?*) from=`cd $from && pwd | sed 's%^/%%'` ;;
  45   *) from=`pwd | sed 's%^/%%'` ;;
  46   esac
  47   ;;
  48 *)
  49   to=$1
  50
  51   if test -d $2; then
  52     from=`echo $2 | sed 's%/*$%%'`
  53   else
  54     from=`echo $2 | sed 's%/*[^/]*$%%'`
  55   fi
  56   ;;
  57 esac
  58
  59 while test -n "$to" && test -n "$from"; do
  60   preto=`echo $to | sed 's%^\([^/]*\)/.*%\1%'`
  61   prefrom=`echo $from | sed 's%^\([^/]*\)/.*%\1%'`
  62
  63   test "$preto" != "$prefrom" && break
  64
  65   to=`echo $to | sed 's%^[^/]*/*\(.*\)$%\1%'`
  66   from=`echo $from | sed 's%^[^/]*/*\(.*\)$%\1%'`
  67 done
  68
  69 while test -n "$from"; do
  70   rfrom="../$rfrom"
  71   from=`echo $from | sed 's%^[^/]*/*%%'`
  72 done
  73
  74 ln -s $rfrom$to $2