relative path

relpath.bash

# 1

# usage: relpath <to> <from>
relpath () { python -c \
  'import os.path, sys; print os.path.relpath(*sys.argv[1:])' "$@"; }


# 2

rel_bin="${bin#"$PREFIX"}"
rel_dir="${dir#"$PREFIX"}"

if [ "$bin" != "$rel_bin" -a "$dir" != "$rel_dir" ]; then
  d="$rel_bin" up=''
  while [ "$d" != / -a "$d" != . ]; do
    up+=../; d="$( dirname "$d" )"
  done
  link_path () { echo "${up%/}$rel_dir/$1"; }
else
  link_path () { $READLINK_F "$dir/$1"; }
fi