the original directory so that
  # - the next file is processed in correct conditions
  # - the temporary file can be removed
  cd "$orig_pwd" || exit 1

  rel=
}


# func_dirname FILE - Return the directory part of FILE.
func_dirname ()
{
  dirname "$1" 2>/dev/null \
  || { echo "$1" | $SED 's!/[^/]*$!!;s!^$!.!'; }
}


# noext FILE - Return FILE with one extension removed:
#   foo.bar.baz -> foo.bar
noext ()
{
  echo "$1" | $SED -e 's/\.[^/.][^/.]*$//'
}


# absolute NAME - Return an absolute path to NAME.
absolute ()
{
  case $1 in
   [\\/]* | ?:[\\/]*)
      # Absolute paths don't need to be expanded.
      echo "$1"
      ;;
   *) absolute_slashes=`echo "$1" | $SED -n 's,.*[^/]\(/*\)$,\1,p'`
      absolute_rel=$orig_pwd/`func_dirname "$1"`
      if test -d "$absolute_rel"; then
        (cd "$absolute_rel" 2>/dev/null \
         && absolute_name=`pwd`/`basename "$1"`"$absolute_slashes"
         echo "$absolute_name")
      else
        error 1 "not a directory: $absolute_rel"
      fi
      ;;
  esac
}


# ensure_dir DIR1 DIR2... - Make sure given directories exist.
ensure_dir ()
{
  for dir
  do
    # Beware that in parallel builds we may have several concurrent
    # attempts to create the directory.  So fail only if "mkdir"
    # failed *and* the directory still does not exist.
    test -d "$dir" \
      || mkdir "$dir" \
      || test -d "$dir" \
      || error 1 "cannot create directory: $dir"
  done
}


# error EXIT_STATUS LINE1 LINE2... - Report an error and exit with
#   failure if EXIT_STATUS is non-null.
error ()
{
  error_status="$1"
  shift
  report "$@"
  if test "$error_status" != 0; then
    exit $error_status
  fi
}


# findprog PROG - Return true if PROG is somewhere in PATH, else false.
findprog ()
{
  saveIFS="$IFS"
  IFS=$path_sep  # break path components at the path separator
  for dir in $PATH; do
    IFS=$saveIFS
    # The basic test for an executable is `test -f $f && test -x $f'.
    # (`test -x' is not enough, because it can also be true for directories.)
    # We have to try this both for $1 and $1.exe.
    #
    # Note: On Cygwin and DJGPP, `test -x' also looks for .exe.  On Cygwin,
    # also `test -f' has this enhancement, but not on DJGPP.  (Both are
    # design decisions, so there is little chance to make them consistent.)
    # Thusly, it seems to be difficult to make use of these enhancements.
    #
    if   { test -f "$dir/$1"     && test -x "$dir/$1"; } \
      || { test -f "$dir/$1.exe" && test -x "$dir/$1.exe"; }; then
      return 0
    fi
  done
  return 1
}

# report LINE1 LINE2... - Echo each argument to stderr.
report ()
{
  for i in "$@"
  do
    echo >&2 "$0: $i"
  done
}


# run COMMAND-LINE - Run COMMAND-LINE verbosely, catching errors as failures.
run ()
{
  verbose "Running $@"
  "$@" 2>&5 1>&2 \
  || error 1 "$1 failed"
}


# verbose WORD1 WORD2... - Echo concatenated WORDs to stderr, if $verb.
verbose ()
{
  if $verb; then
    echo >&2 "$0: $@"
  fi
}


#