File: datauri.py
   1 #!/usr/bin/python3
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright © 2024 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the “Software”), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 from base64 import b64encode
  27 from mimetypes import guess_type
  28 from sys import argv, exit, stderr, stdout
  29 
  30 
  31 info = '''
  32 datauri [options...] [filepaths/URIs...]
  33 
  34 Turn each named input (file/URI) given into a data-URI line.
  35 
  36 Data-URIs are base64-encoded text representations of arbitrary data, which
  37 include their payload's MIME-type, and which are directly useable/shareable
  38 in web-browsers as links, despite not looking like normal links/URIs.
  39 '''
  40 
  41 # no args or a leading help-option arg means show the help message and quit
  42 if len(argv) == 1 or argv[1] in ('-h', '--h', '-help', '--help'):
  43     print(info.strip(), file=stderr)
  44     exit(0)
  45 
  46 
  47 def seems_url(s: str) -> bool:
  48     protocols = ('https://', 'http://', 'file://', 'ftp://', 'data:')
  49     return any(s.startswith(p) for p in protocols)
  50 
  51 
  52 def handle_input(w, src, path: str) -> None:
  53     mime = ''
  54 
  55     # get MIME-type from response headers, if input is an HTTP response
  56     if hasattr(inp, 'getheader'):
  57         mime = inp.getheader('content-type')
  58 
  59     # failing that, guess the MIME-type from the input's name/URI
  60     if not mime:
  61         (mime, _) = guess_type(path)
  62 
  63     if not mime:
  64         raise Exception(f'{path}: can\'t guess MIME-type')
  65 
  66     w.write(b'data:')
  67     w.write(bytes(mime, encoding='utf-8'))
  68     w.write(b';base64,')
  69     w.write(b64encode(src.read()))
  70     w.write(b'\n')
  71 
  72 
  73 try:
  74     if '-' in argv:
  75         raise Exception('can\'t use standard input, only named sources')
  76 
  77     if any(seems_url(e) for e in argv):
  78         from urllib.request import urlopen
  79 
  80     for path in argv[1:]:
  81         if seems_url(path):
  82             with urlopen(path) as inp:
  83                 handle_input(stdout.buffer, inp, path)
  84             continue
  85 
  86         with open(path, mode='rb') as inp:
  87             handle_input(stdout.buffer, inp, path)
  88 except BrokenPipeError:
  89     # quit quietly, instead of showing a confusing error message
  90     stderr.close()
  91 except KeyboardInterrupt:
  92     exit(2)
  93 except Exception as e:
  94     print(f'\x1b[31m{e}\x1b[0m', file=stderr)
  95     exit(1)