File: gobble.py
   1 #!/usr/bin/python3
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright © 2020-2025 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 io import BytesIO
  27 from os import close, pipe, write
  28 from subprocess import call
  29 from sys import argv, exit, stderr, stdin, stdout
  30 
  31 
  32 info = '''
  33 gobble [command...] [args...]
  34 
  35 Read all bytes from standard input, and only then emit them out, or run
  36 the command given, sending those bytes to its standard input.
  37 '''
  38 
  39 
  40 if len(argv) > 1 and argv[1] in ('-h', '--h', '-help', '--help'):
  41     print(info.strip())
  42     exit(0)
  43 
  44 
  45 try:
  46     if len(argv) > 1:
  47         r, w = pipe()
  48         data = stdin.buffer.read()
  49         # os.write always hangs when given more than a few kilobytes
  50         chunk_size = 4 * 1024
  51         while len(data) >= chunk_size:
  52             write(w, data[:chunk_size])
  53             data = data[chunk_size:]
  54         write(w, data)
  55         close(w)
  56         exit(call(argv[1:], stdin=r, stdout=stdout, stderr=stderr))
  57     else:
  58         stdout.buffer.write(stdin.buffer.read())
  59 except BrokenPipeError:
  60     stderr.close()
  61     exit(0)
  62 except KeyboardInterrupt:
  63     exit(2)
  64 except Exception as e:
  65     print(f'\x1b[31m{e}\x1b[0m', file=stderr)
  66     exit(1)