# Path information is stored on separate lines in XXXdirs.
# We extract each directory exists and add it to the appropriate PATH.
#

# Location of the XXXdirs files.
DIR="$HOME/.profile.d"

# Set one path to be the same as another.
function copypath() {
  newpath="$1"; shift
  oldpath="$1"; shift

  # Sanitise and export.
  path="$(eval echo \$$oldpath)"
  [ -z "$path" ] || eval "export $newpath='$path'"

  unset path newpath oldpath
}

# Set a path from directories.
function makepath() {
  newpath="$1"; shift
  dirs="$1"; shift

  # Check the file exists.
  [ -e "$DIR/$dirs" ] || return

  # Set IFS to newline only so that we can read $(embedded shell commands).
  JGD=$IFS
  IFS='
'
  # Read them.
  path=
  while read dir; do
    dir=$(eval echo "$dir")
    [ -d "$dir" ] || continue

    path="$path:$dir"
  done < "$DIR/$dirs"
  unset dir

  # Restore IFS.
  IFS=$JGD
  unset JGD

  # Sanitise path.
  path=${path#:}
  [ -z "$path" ] && return

  # Export.
  eval "export $newpath='$path'"

  unset path newpath dirs
}

makepath PATH bindirs
makepath C_INCLUDE_PATH incdirs
copypath CPLUS_INCLUDE_PATH C_INCLUDE_PATH
makepath LD_LIBRARY_PATH libdirs
copypath LD_RUN_PATH PATH
makepath MANPATH mandirs
makepath PKG_CONFIG_PATH pkgdirs

unset dirs copypath makepath newpath