File: tbp.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 info = ''' 27 tbp [options...] [python expression] [files/URIs...] 28 29 30 Transform Bytes with Python runs a python expression on each whole-input, 31 read as a bytes-type value. 32 33 The expression can use either `v`, `value`, `d`, or `data` for the current 34 input. 35 36 Input-sources can be either files or web-URIs. When not given any explicit 37 named sources, the standard input is used. It's even possible to reuse the 38 standard input using multiple single dashes (-) in the order needed: stdin 39 is only read once in this case, and kept for later reuse. 40 41 When the expression results in None, the current input is ignored. When the 42 expression results in a boolean, this determines whether the whole input is 43 copied/appended back to the standard output, or ignored. 44 ''' 45 46 47 from sys import argv, exit, stderr, stdin, stdout 48 from time import sleep 49 from typing import Generator 50 51 52 if len(argv) < 2: 53 print(info.strip(), file=stderr) 54 exit(0) 55 if len(argv) == 2 and argv[1] in ('-h', '--h', '-help', '--help'): 56 print(info.strip()) 57 exit(0) 58 59 60 class Skip: 61 pass 62 63 skip = Skip() 64 65 def cond(*args): 66 if len(args) == 0: 67 return None 68 69 for i, e in enumerate(args): 70 if i % 2 == 0 and i < len(args) - 1 and e: 71 return args[i + 1] 72 73 return args[-1] if len(args) % 2 == 1 else None 74 75 def rescue(attempt, fallback = None): 76 try: 77 return attempt() 78 except Exception as e: 79 if callable(fallback): 80 return fallback(e) 81 return fallback 82 83 catch = rescue 84 recover = rescue 85 rescued = rescue 86 87 def wait(seconds, result): 88 t = (int, float) 89 if (not isinstance(seconds, t)) and isinstance(result, t): 90 seconds, result = result, seconds 91 sleep(seconds) 92 return result 93 94 delay = wait 95 96 def uint_big_endian(src, size, start=0): 97 if not isinstance(src, bytes): 98 return ValueError('can only get unsigned integers from bytes') 99 if start + size >= len(src): 100 msg = f'not enough bytes for {8 * size}-bit unsigned integers' 101 raise ValueError(msg) 102 return sum(int(src[start + i]) << (8 * i) for i in range(size, 0, -1)) 103 104 def uint16_be(src, start=0): 105 return uint_big_endian(src, 2, start) 106 107 uint16be = uint16_be 108 109 def uint32_be(src, start=0): 110 return uint_big_endian(src, 4, start) 111 112 uint32be = uint32_be 113 114 def uint64_be(src, start=0): 115 return uint_big_endian(src, 8, start) 116 117 uint64be = uint64_be 118 119 def uint_little_endian(src, size, start=0): 120 if not isinstance(src, bytes): 121 return ValueError('can only get unsigned integers from bytes') 122 if start + size >= len(src): 123 msg = f'not enough bytes for {8 * size}-bit unsigned integers' 124 raise ValueError(msg) 125 return sum(int(src[start + i]) << (8 * i) for i in range(size)) 126 127 def uint16_le(src, start=0): 128 return uint_little_endian(src, 2, start) 129 130 uint16le = uint16_le 131 132 def uint32_le(src, start=0): 133 return uint_little_endian(src, 4, start) 134 135 uint32le = uint32_le 136 137 def uint64_le(src, start=0): 138 return uint_little_endian(src, 8, start) 139 140 uint64le = uint64_le 141 142 143 no_input_opts = ( 144 '=', '-n', '--n', '-nil', '--nil', '-none', '--none', '-null', '--null', 145 ) 146 string_opts = ('-s', '--s', '-str', '--str', '-string', '--string') 147 148 args = argv[1:] 149 load_input = True 150 string_input = False 151 expression = None 152 153 # handle all other leading options; the explicit help options are 154 # handled earlier in the script 155 while len(args) > 0: 156 if args[0] in no_input_opts: 157 load_input = False 158 args = args[1:] 159 continue 160 161 if args[0] in string_opts: 162 string_input = True 163 args = args[1:] 164 continue 165 166 break 167 168 if len(args) > 0: 169 expression = args[0] 170 args = args[1:] 171 172 if expression is None: 173 print(info.strip(), file=stderr) 174 exit(0) 175 176 177 def make_open_read(open): 178 'Restrict the file-open func to a read-only-binary file-open func.' 179 def open_read(name): 180 return open(name, mode='rb') 181 return open_read 182 183 184 def fail(msg, code = 1): 185 print(f'\x1b[31m{str(msg)}\x1b[0m', file=stderr) 186 exit(code) 187 188 189 def message(msg, result = None): 190 print(msg, file=stderr) 191 return result 192 193 msg = message 194 195 196 def seemsurl(s): 197 protocols = ('https://', 'http://', 'file://', 'ftp://', 'data:') 198 return any(s.startswith(p) for p in protocols) 199 200 201 def tobytes(x): 202 if isinstance(x, (bytearray, bytes)): 203 return x 204 if isinstance(x, (bool, int)): 205 return bytes((int(x), )) 206 if isinstance(x, float): 207 return bytes(str(x), encoding='utf-8') 208 if isinstance(x, str): 209 return bytes(x, encoding='utf-8') 210 return bytes(x) 211 212 213 def tointorbytes(x): 214 return x if isinstance(x, int) else tobytes(x) 215 216 217 def adapt_result(x, default): 218 if x is True: 219 return default 220 if x is False: 221 return None 222 223 if isinstance(x, Skip): 224 return None 225 226 if callable(x): 227 return x(default) 228 return x 229 230 231 def emit_result(w, x): 232 if x is None: 233 return 234 235 if isinstance(x, int): 236 w.write(tobytes(x)) 237 return 238 239 if isinstance(x, (list, tuple, range, Generator)): 240 for e in x: 241 w.write(tobytes(e)) 242 return 243 244 w.write(tobytes(x)) 245 246 247 def eval_expr(expr, using): 248 global v, val, value, d, dat, data 249 # offer several aliases for the variable with the input bytes 250 v = val = value = d = dat = data = using 251 return adapt_result(eval(expr), using) 252 253 254 cr = '\r' if string_input else b'\r' 255 crlf = '\r\n' if string_input else b'\r\n' 256 dquo = '"' if string_input else b'"' 257 dquote = '"' if string_input else b'"' 258 empty = '' if string_input else b'' 259 lcurly = '{' if string_input else b'{' 260 lf = '\n' if string_input else b'\n' 261 rcurly = '}' if string_input else b'}' 262 space = ' ' if string_input else b' ' 263 squo = '\'' if string_input else b'\'' 264 squote = '\'' if string_input else b'\'' 265 tab = '\t' if string_input else b'\t' 266 # utf8bom = '\xef\xbb\xbf' if string_input else b'\xef\xbb\xbf' 267 if string_input: 268 bom = { 269 'utf8': '\xef\xbb\xbf', 270 'utf16be': '\xfe\xff', 271 'utf16le': '\xff\xfe', 272 'utf32be': '\x00\x00\xfe\xff', 273 'utf32le': '\xff\xfe\x00\x00', 274 } 275 else: 276 bom = { 277 'utf8': b'\xef\xbb\xbf', 278 'utf16be': b'\xfe\xff', 279 'utf16le': b'\xff\xfe', 280 'utf32be': b'\x00\x00\xfe\xff', 281 'utf32le': b'\xff\xfe\x00\x00', 282 } 283 284 nil = None 285 none = None 286 null = None 287 288 exec = None 289 open = make_open_read(open) 290 291 modules_opts = ( 292 '-m', '--m', '-mod', '--mod', '-module', '--module', 293 '-modules', '--modules', 294 ) 295 more_modules_opts = ('-mm', '--mm', '-more', '--more') 296 297 while len(args) > 0: 298 if args[0] == '--': 299 args = args[1:] 300 break 301 302 if args[0] in no_input_opts: 303 no_input = True 304 args = args[1:] 305 continue 306 307 if args[0] in modules_opts: 308 try: 309 if len(args) < 2: 310 msg = 'a module name or a comma-separated list of modules' 311 raise Exception('expected ' + msg) 312 313 g = globals() 314 from importlib import import_module 315 for e in args[1].split(','): 316 g[e] = import_module(e) 317 318 g = None 319 import_module = None 320 args = args[2:] 321 except Exception as e: 322 fail(e, 1) 323 324 continue 325 326 if args[0] in more_modules_opts: 327 import functools, itertools, json, math, random, statistics, string, time 328 args = args[1:] 329 continue 330 331 break 332 333 334 try: 335 if not expression or expression == '.': 336 expression = 'data' 337 expression = compile(expression, expression, 'eval') 338 339 got_stdin = False 340 all_stdin = None 341 dashes = args.count('-') 342 343 data = None 344 345 if not load_input: 346 emit_result(stdout.buffer, eval_expr(expression, None)) 347 exit(0) 348 349 if any(seemsurl(name) for name in args): 350 from urllib.request import urlopen 351 352 for name in args: 353 if name == '-': 354 if dashes > 1: 355 if not got_stdin: 356 all_stdin = stdin.buffer.read() 357 got_stdin = True 358 data = all_stdin 359 else: 360 data = stdin.buffer.read() 361 362 if string_input: 363 data = s = str(data, encoding='utf-8') 364 elif seemsurl(name): 365 with urlopen(name) as inp: 366 data = inp.read() 367 else: 368 with open(name) as inp: 369 data = inp.read() 370 371 if string_input: 372 data = s = str(data, encoding='utf-8') 373 emit_result(stdout.buffer, eval_expr(expression, data)) 374 375 if len(args) == 0: 376 data = stdin.buffer.read() 377 if string_input: 378 data = s = str(data, encoding='utf-8') 379 emit_result(stdout.buffer, eval_expr(expression, data)) 380 except BrokenPipeError: 381 # quit quietly, instead of showing a confusing error message 382 stderr.close() 383 exit(0) 384 except KeyboardInterrupt: 385 exit(2) 386 except Exception as e: 387 s = str(e) 388 s = s if s else '<generic exception>' 389 print(f'\x1b[31m{s}\x1b[0m', file=stderr) 390 exit(1)