File: fizz.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 # fizz [options...] 27 # 28 # Emit random output bytes, to help `fuzz-test` other tools. 29 # 30 # All (optional) leading options start with either single or double-dash, 31 # and most of them change the style/color used. Some of the options are, 32 # shown in their single-dash form: 33 # 34 # -h show this help message 35 # -help show this help message 36 # 37 # -n use the next argument as the output byte-count 38 # -ascii only emit bytes in the valid ASCII text-range 39 # -text only emit bytes in the valid ASCII text-range 40 41 42 from random import randint, seed 43 from sys import argv, exit, stderr, stdout 44 from time import time 45 46 47 # info is the help message shown when asked to 48 info = ''' 49 fizz [options...] 50 51 Emit random output bytes, to help `fuzz-test` other tools. 52 53 All (optional) leading options start with either single or double-dash, 54 and most of them change the style/color used. Some of the options are, 55 shown in their single-dash form: 56 57 -h show this help message 58 -help show this help message 59 60 -n use the next argument as the output byte-count 61 -ascii only emit bytes in the valid ASCII text-range 62 -text only emit bytes in the valid ASCII text-range 63 '''.strip() 64 65 # handle standard help cmd-line options, quitting right away in that case 66 if len(argv) == 2 and argv[1] in ('-h', '--h', '-help', '--help'): 67 print(info, file=stderr) 68 exit(0) 69 70 71 def fail(msg, code: int = 1) -> None: 72 '''Show the error message given, and quit the app right away.''' 73 print(f'\x1b[31m{msg}\x1b[0m', file=stderr) 74 exit(code) 75 76 77 def emit_bytes(w, n: int, low: int = 0, high: int = 255) -> None: 78 '''Here's what the whole script comes down to.''' 79 80 # prevent trying to create non-positive-sized byte-arrays; using 81 # negative values in their constructor causes exceptions 82 if n < 1: 83 return 84 85 # looking up global vars is slower in older versions of python, 86 # and this func is repeatedly looked-up in loops, possibly 87 # millions of times 88 local_randint = randint 89 90 # considerably speed-up the whole script, by minimizing calls to 91 # func `write` via pre-filled `chunks` of random bytes; using 92 # size 64 doesn't seem to speed things further, compared to 32 93 chunk_size = 32 94 chunk = bytearray(chunk_size) 95 while n >= chunk_size: 96 for i in range(chunk_size): 97 chunk[i] = local_randint(low, high) 98 w.write(chunk) 99 n -= chunk_size 100 101 # don't forget the last few output bytes 102 chunk = bytearray(n) 103 for i in range(n): 104 chunk[i] = local_randint(low, high) 105 w.write(chunk) 106 107 108 # handle command-line options 109 n = 1_024 110 text_only = False 111 start_args = 1 112 if start_args < len(argv): 113 try: 114 n = int(float(argv[start_args])) 115 if n < 0: 116 n = -n 117 start_args += 1 118 except: 119 pass 120 while start_args < len(argv) and argv[start_args].startswith('-'): 121 l = argv[start_args].lstrip('-').lower() 122 if l in ('ascii', 'text'): 123 text_only = True 124 start_args += 1 125 continue 126 if l in ('n'): 127 if start_args + 1 >= len(argv): 128 fail('missing actual byte-count in cmd-line arguments', 1) 129 try: 130 n = int(float(argv[start_args + 1])) 131 if n < 0: 132 n = -n 133 except Exception as e: 134 fail(e, 1) 135 start_args += 2 136 continue 137 break 138 args = argv[start_args:] 139 140 try: 141 seed(time()) 142 if text_only: 143 emit_bytes(stdout.buffer, n, ord(' '), ord('~')) 144 else: 145 emit_bytes(stdout.buffer, n, 0, 255) 146 except BrokenPipeError: 147 # quit quietly, instead of showing a confusing error message 148 stderr.flush() 149 stderr.close() 150 except KeyboardInterrupt: 151 # quit quietly, instead of showing a confusing error message 152 stderr.flush() 153 stderr.close() 154 exit(2) 155 except Exception as e: 156 fail(e, 1)