forked from Imagelibrary/littlefs
7cfcc1af1d
This seems like a more fitting name now that this script has evolved
into more of a general purpose high-level CSV tool.
Unfortunately this does conflict with the standard csv module in Python,
breaking every script that imports csv (which is most of them).
Fortunately, Python is flexible enough to let us remove the current
directory before imports with a bit of an ugly hack:
# prevent local imports
__import__('sys').path.pop(0)
These scripts are intended to be standalone anyways, so this is probably
a good pattern to adopt.
91 lines
2.3 KiB
Python
Executable File
91 lines
2.3 KiB
Python
Executable File
#!/usr/bin/env python3
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# prevent local imports
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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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import functools as ft
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import operator as op
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def openio(path, mode='r', buffering=-1):
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# allow '-' for stdin/stdout
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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 popc(x):
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return bin(x).count('1')
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def parity(x):
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return popc(x) & 1
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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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print('%01x' % parity(ft.reduce(
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op.xor,
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bytes(int(path, 16) for path in paths),
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0)))
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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('%01x' % parity(ft.reduce(
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op.xor,
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path.encode('utf8'),
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0)))
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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 parity
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xor = 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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xor = ft.reduce(op.xor, block, xor)
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# print what we found
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if path is not None:
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print('%01x %s' % (parity(xor), path))
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else:
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print('%01x' % parity(xor))
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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 parity.",
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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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