forked from Imagelibrary/littlefs
9085f1fdd9
This matches the behavior of paths and helps figure out which string is associated with which crc32c/parity when checksumming multiple strings: $ ./scripts/crc32c.py -s hi hello f59dd9c2 hi 9a71bb4c hello It also might help clear up confusion if someone forgets to quote a string with spaces inside it.
96 lines
2.5 KiB
Python
Executable File
96 lines
2.5 KiB
Python
Executable File
#!/usr/bin/env python3
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# prevent local imports
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if __name__ == "__main__":
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__import__('sys').path.pop(0)
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import io
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import os
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import struct
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import sys
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try:
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import crc32c as crc32c_lib
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except ModuleNotFoundError:
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crc32c_lib = None
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# open with '-' for stdin/stdout
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def openio(path, mode='r', buffering=-1):
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import os
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if path == '-':
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if 'r' in mode:
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return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
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else:
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return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
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else:
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return open(path, mode, buffering)
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def crc32c(data, crc=0):
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if crc32c_lib is not None:
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return crc32c_lib.crc32c(data, crc)
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else:
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crc ^= 0xffffffff
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for b in data:
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crc ^= b
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for j in range(8):
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crc = (crc >> 1) ^ ((crc & 1) * 0x82f63b78)
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return 0xffffffff ^ crc
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def main(paths, **args):
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# interpret as sequence of hex bytes
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if args.get('hex'):
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bytes_ = [b for path in paths for b in path.split()]
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print('%08x' % crc32c(bytes(int(b, 16) for b in bytes_)))
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# interpret as strings
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elif args.get('string'):
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for path in paths:
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print('%08x %s' % (crc32c(path.encode('utf8')), path))
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# default to interpreting as paths
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else:
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if not paths:
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paths = [None]
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for path in paths:
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with openio(path or '-', 'rb') as f:
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# calculate crc
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crc = 0
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while True:
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block = f.read(io.DEFAULT_BUFFER_SIZE)
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if not block:
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break
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crc = crc32c(block, crc)
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# print what we found
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if path is not None:
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print('%08x %s' % (crc, path))
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else:
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print('%08x' % crc)
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if __name__ == "__main__":
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import argparse
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import sys
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parser = argparse.ArgumentParser(
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description="Calculates crc32cs.",
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allow_abbrev=False)
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parser.add_argument(
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'paths',
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nargs='*',
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help="Paths to read. Reads stdin by default.")
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parser.add_argument(
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'-x', '--hex',
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action='store_true',
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help="Interpret as a sequence of hex bytes.")
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parser.add_argument(
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'-s', '--string',
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action='store_true',
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help="Interpret as strings.")
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sys.exit(main(**{k: v
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for k, v in vars(parser.parse_intermixed_args()).items()
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if v is not None}))
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