Improve error reporting when renaming fonts.

OpenType fonts (*.otf) are not currently supported. They are copied to the destination without renaming.

XML files are also copied in case they are passed there by mistake.

Usage: build_font.py /path/to/input_font.ttf /path/to/output_font.ttf

Usage: build_font_single.py /path/to/input_font.ttf /path/to/output_font.ttf

"""

def main(argv):

  if len(argv) < 2:

    sys.exit('Usage: build_font.py /path/to/input/font.ttf /path/to/out/font.ttf')

    print 'Incorrect usage: ' + str(argv)

    sys.exit('Usage: build_font_single.py /path/to/input/font.ttf /path/to/out/font.ttf')

  dest_path = argv[-1]

  input_path = argv[0]

  extension = os.path.splitext(input_path)[1].lower()