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 64 skip = Skip() 65 66 67 def cond(*args): 68 if len(args) == 0: 69 return None 70 71 for i, e in enumerate(args): 72 if i % 2 == 0 and i < len(args) - 1 and e: 73 return args[i + 1] 74 75 return args[-1] if len(args) % 2 == 1 else None 76 77 78 def rescue(attempt, fallback = None): 79 try: 80 return attempt() 81 except Exception as e: 82 if callable(fallback): 83 return fallback(e) 84 return fallback 85 86 catch = rescue 87 recover = rescue 88 rescued = rescue 89 90 91 def wait(seconds, result): 92 t = (int, float) 93 if (not isinstance(seconds, t)) and isinstance(result, t): 94 seconds, result = result, seconds 95 sleep(seconds) 96 return result 97 98 delay = wait 99 100 101 def uint_big_endian(src, size, start=0): 102 if not isinstance(src, bytes): 103 return ValueError('can only get unsigned integers from bytes') 104 if start + size >= len(src): 105 msg = f'not enough bytes for {8 * size}-bit unsigned integers' 106 raise ValueError(msg) 107 return sum(int(src[start + i]) << (8 * i) for i in range(size, 0, -1)) 108 109 110 def uint16_be(src, start=0): 111 return uint_big_endian(src, 2, start) 112 113 uint16be = uint16_be 114 115 def uint32_be(src, start=0): 116 return uint_big_endian(src, 4, start) 117 118 uint32be = uint32_be 119 120 def uint64_be(src, start=0): 121 return uint_big_endian(src, 8, start) 122 123 uint64be = uint64_be 124 125 126 def uint_little_endian(src, size, start=0): 127 if not isinstance(src, bytes): 128 return ValueError('can only get unsigned integers from bytes') 129 if start + size >= len(src): 130 msg = f'not enough bytes for {8 * size}-bit unsigned integers' 131 raise ValueError(msg) 132 return sum(int(src[start + i]) << (8 * i) for i in range(size)) 133 134 135 def uint16_le(src, start=0): 136 return uint_little_endian(src, 2, start) 137 138 uint16le = uint16_le 139 140 def uint32_le(src, start=0): 141 return uint_little_endian(src, 4, start) 142 143 uint32le = uint32_le 144 145 def uint64_le(src, start=0): 146 return uint_little_endian(src, 8, start) 147 148 uint64le = uint64_le 149 150 151 no_input_opts = ( 152 '=', '-n', '--n', '-nil', '--nil', '-none', '--none', '-null', '--null', 153 ) 154 string_opts = ('-s', '--s', '-str', '--str', '-string', '--string') 155 156 args = argv[1:] 157 load_input = True 158 string_input = False 159 expression = None 160 161 # handle all other leading options; the explicit help options are 162 # handled earlier in the script 163 while len(args) > 0: 164 if args[0] in no_input_opts: 165 load_input = False 166 args = args[1:] 167 continue 168 169 if args[0] in string_opts: 170 string_input = True 171 args = args[1:] 172 continue 173 174 break 175 176 if len(args) > 0: 177 expression = args[0] 178 args = args[1:] 179 180 if expression is None: 181 print(info.strip(), file=stderr) 182 exit(0) 183 184 185 def make_open_read(open): 186 'Restrict the file-open func to a read-only-binary file-open func.' 187 def open_read(name): 188 return open(name, mode='rb') 189 return open_read 190 191 192 def fail(msg, code = 1): 193 print(f'\x1b[31m{str(msg)}\x1b[0m', file=stderr) 194 exit(code) 195 196 197 def message(msg, result = None): 198 print(msg, file=stderr) 199 return result 200 201 msg = message 202 203 204 def seemsurl(s): 205 protocols = ('https://', 'http://', 'file://', 'ftp://', 'data:') 206 return any(s.startswith(p) for p in protocols) 207 208 209 def tobytes(x): 210 if isinstance(x, (bytearray, bytes)): 211 return x 212 if isinstance(x, (bool, int)): 213 return bytes((int(x), )) 214 if isinstance(x, float): 215 return bytes(str(x), encoding='utf-8') 216 if isinstance(x, str): 217 return bytes(x, encoding='utf-8') 218 return bytes(x) 219 220 221 def tointorbytes(x): 222 return x if isinstance(x, int) else tobytes(x) 223 224 225 def adapt_result(x, default): 226 if x is True: 227 return default 228 if x is False: 229 return None 230 231 if isinstance(x, Skip): 232 return None 233 234 if callable(x): 235 return x(default) 236 return x 237 238 239 def emit_result(w, x): 240 if x is None: 241 return 242 243 if isinstance(x, int): 244 w.write(tobytes(x)) 245 return 246 247 if isinstance(x, (list, tuple, range, Generator)): 248 for e in x: 249 w.write(tobytes(e)) 250 return 251 252 w.write(tobytes(x)) 253 254 255 def eval_expr(expr, using): 256 global v, val, value, d, dat, data 257 # offer several aliases for the variable with the input bytes 258 v = val = value = d = dat = data = using 259 return adapt_result(eval(expr), using) 260 261 262 cr = '\r' if string_input else b'\r' 263 crlf = '\r\n' if string_input else b'\r\n' 264 dquo = '"' if string_input else b'"' 265 dquote = '"' if string_input else b'"' 266 empty = '' if string_input else b'' 267 lcurly = '{' if string_input else b'{' 268 lf = '\n' if string_input else b'\n' 269 rcurly = '}' if string_input else b'}' 270 space = ' ' if string_input else b' ' 271 squo = '\'' if string_input else b'\'' 272 squote = '\'' if string_input else b'\'' 273 tab = '\t' if string_input else b'\t' 274 # utf8bom = '\xef\xbb\xbf' if string_input else b'\xef\xbb\xbf' 275 if string_input: 276 bom = { 277 'utf8': '\xef\xbb\xbf', 278 'utf16be': '\xfe\xff', 279 'utf16le': '\xff\xfe', 280 'utf32be': '\x00\x00\xfe\xff', 281 'utf32le': '\xff\xfe\x00\x00', 282 } 283 else: 284 bom = { 285 'utf8': b'\xef\xbb\xbf', 286 'utf16be': b'\xfe\xff', 287 'utf16le': b'\xff\xfe', 288 'utf32be': b'\x00\x00\xfe\xff', 289 'utf32le': b'\xff\xfe\x00\x00', 290 } 291 292 nil = None 293 none = None 294 null = None 295 296 exec = None 297 open = make_open_read(open) 298 299 modules_opts = ( 300 '-m', '--m', '-mod', '--mod', '-module', '--module', 301 '-modules', '--modules', 302 ) 303 more_modules_opts = ('-mm', '--mm', '-more', '--more') 304 305 while len(args) > 0: 306 if args[0] in no_input_opts: 307 no_input = True 308 args = args[1:] 309 continue 310 311 if args[0] in modules_opts: 312 try: 313 if len(args) < 2: 314 msg = 'a module name or a comma-separated list of modules' 315 raise Exception('expected ' + msg) 316 317 g = globals() 318 from importlib import import_module 319 for e in args[1].split(','): 320 g[e] = import_module(e) 321 322 g = None 323 import_module = None 324 args = args[2:] 325 except Exception as e: 326 fail(e, 1) 327 328 continue 329 330 if args[0] in more_modules_opts: 331 import functools, itertools, json, math, random, statistics, string, time 332 args = args[1:] 333 continue 334 335 break 336 337 338 try: 339 if not expression or expression == '.': 340 expression = 'data' 341 expression = compile(expression, expression, 'eval') 342 343 got_stdin = False 344 all_stdin = None 345 dashes = args.count('-') 346 347 data = None 348 349 if not load_input: 350 emit_result(stdout.buffer, eval_expr(expression, None)) 351 exit(0) 352 353 if any(seemsurl(name) for name in args): 354 from urllib.request import urlopen 355 356 for name in args: 357 if name == '-': 358 if dashes > 1: 359 if not got_stdin: 360 all_stdin = stdin.buffer.read() 361 got_stdin = True 362 data = all_stdin 363 else: 364 data = stdin.buffer.read() 365 366 if string_input: 367 data = s = str(data, encoding='utf-8') 368 elif seemsurl(name): 369 with urlopen(name) as inp: 370 data = inp.read() 371 else: 372 with open(name) as inp: 373 data = inp.read() 374 375 if string_input: 376 data = s = str(data, encoding='utf-8') 377 emit_result(stdout.buffer, eval_expr(expression, data)) 378 379 if len(args) == 0: 380 data = stdin.buffer.read() 381 if string_input: 382 data = s = str(data, encoding='utf-8') 383 emit_result(stdout.buffer, eval_expr(expression, data)) 384 except BrokenPipeError: 385 # quit quietly, instead of showing a confusing error message 386 stderr.close() 387 exit(0) 388 except KeyboardInterrupt: 389 exit(2) 390 except Exception as e: 391 s = str(e) 392 s = s if s else '<generic exception>' 393 print(f'\x1b[31m{s}\x1b[0m', file=stderr) 394 exit(1)