File: minitb.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 info = ''' 27 tb [options...] [python expression] [filepath/URI...] 28 29 This is the MINImal version of the Transform Bytes tool. 30 ''' 31 32 33 from sys import argv, exit, stderr, stdin, stdout 34 from typing import Generator 35 36 37 if len(argv) < 2: 38 print(info.strip(), file=stderr) 39 exit(0) 40 if len(argv) == 2 and argv[1] in ('-h', '--h', '-help', '--help'): 41 print(info.strip()) 42 exit(0) 43 44 45 class Skip: 46 pass 47 48 49 skip = Skip() 50 51 52 def rescue(attempt, fallback = None): 53 try: 54 return attempt() 55 except Exception as e: 56 if callable(fallback): 57 return fallback(e) 58 return fallback 59 60 catch = rescue 61 catched = rescue 62 caught = rescue 63 recover = rescue 64 recovered = rescue 65 rescued = rescue 66 67 68 no_input_opts = ( 69 '=', '-n', '--n', '-nil', '--nil', '-none', '--none', '-null', '--null', 70 ) 71 more_modules_opts = ('-mm', '--mm', '-more', '--more') 72 73 args = argv[1:] 74 load_input = True 75 expression = None 76 77 # handle all other leading options; the explicit help options are 78 # handled earlier in the script 79 while len(args) > 0: 80 if args[0] in no_input_opts: 81 load_input = False 82 args = args[1:] 83 continue 84 85 if args[0] in more_modules_opts: 86 import functools 87 import itertools 88 import math 89 import random 90 import statistics 91 import string 92 import time 93 args = args[1:] 94 continue 95 96 break 97 98 if len(args) > 0: 99 expression = args[0] 100 args = args[1:] 101 102 if expression is None: 103 print(info.strip(), file=stderr) 104 exit(0) 105 106 107 def make_open_read(open): 108 'Restrict the file-open func to a read-only-binary file-open func.' 109 def open_readonly(name): 110 return open(name, mode='rb') 111 return open_readonly 112 113 114 def seems_url(s): 115 protocols = ('https://', 'http://', 'file://', 'ftp://', 'data:') 116 return any(s.startswith(p) for p in protocols) 117 118 119 def tobytes(x): 120 if isinstance(x, bytes): 121 return x 122 if isinstance(x, (bool, int)): 123 return bytes(int(x)) 124 if isinstance(x, float): 125 return bytes(str(x), encoding='utf-8') 126 if isinstance(x, str): 127 return bytes(x, encoding='utf-8') 128 return bytes(x) 129 130 131 def tointorbytes(x): 132 return x if isinstance(x, int) else tobytes(x) 133 134 135 open_read = make_open_read(open) 136 open = open_read 137 138 exec = None 139 140 141 def adapt_result(x, default): 142 if x is True: 143 return default 144 if x is False: 145 return None 146 147 if isinstance(x, Skip): 148 return None 149 150 if callable(x): 151 return x(default) 152 return x 153 154 155 def emit_result(w, x): 156 if x is None: 157 return 158 159 if isinstance(x, (list, tuple, range, Generator)): 160 for e in x: 161 w.write(tobytes(e)) 162 return 163 164 w.write(tobytes(x)) 165 166 167 def eval_expr(expr, using): 168 global v, val, value, d, dat, data 169 # offer several aliases for the variable with the input bytes 170 v = val = value = d = dat = data = using 171 return adapt_result(eval(expr), using) 172 173 174 import functools 175 import itertools 176 import math 177 import random 178 import statistics 179 import string 180 import time 181 182 183 try: 184 if not expression or expression == '.': 185 expression = 'data' 186 expression = compile(expression, expression, 'eval') 187 188 got_stdin = False 189 all_stdin = None 190 dashes = args.count('-') 191 192 if any(seems_url(name) for name in args): 193 from urllib.request import urlopen 194 195 data = None 196 197 if load_input: 198 for name in args: 199 if name == '-': 200 if dashes > 1: 201 if not got_stdin: 202 all_stdin = stdin.buffer.read() 203 got_stdin = True 204 data = all_stdin 205 else: 206 data = stdin.buffer.read() 207 elif seems_url(name): 208 with urlopen(name) as inp: 209 data = inp.read() 210 else: 211 with open_read(name) as inp: 212 data = inp.read() 213 214 emit_result(stdout.buffer, eval_expr(expression, data)) 215 216 if len(args) == 0: 217 data = stdin.buffer.read() 218 emit_result(stdout.buffer, eval_expr(expression, data)) 219 else: 220 emit_result(stdout.buffer, eval_expr(expression, None)) 221 except BrokenPipeError: 222 # quit quietly, instead of showing a confusing error message 223 stderr.close() 224 exit(0) 225 except KeyboardInterrupt: 226 # stderr.close() 227 exit(2) 228 except Exception as e: 229 s = str(e) 230 s = s if s else '<generic exception>' 231 print(f'\x1b[31m{s}\x1b[0m', file=stderr) 232 exit(1)