Files
littlefs/scripts/crc32c.py
Christopher Haster 262ad7c08e scripts: Simplified dbgtag.py, tweaked -x/--hex decoding
This drops the option to read tags from a disk file. I don't think I've
ever used this, and it requires quite a bit of circuitry to implement.

Also dropped -s/--string, because most tags can't be represented as
strings?

And tweaked -x/--hex flags to correctly parse spaces in arguments, so
now these are equivalent:

- ./scripts/dbgtag.py -x 00 03 00 08
- ./scripts/dbgtag.py -x "00 03 00 08"
2025-04-16 15:21:54 -05:00

88 lines
2.3 KiB
Python
Executable File

#!/usr/bin/env python3
# prevent local imports
if __name__ == "__main__":
__import__('sys').path.pop(0)
import io
import os
import struct
import sys
def openio(path, mode='r', buffering=-1):
# allow '-' for stdin/stdout
import os
if path == '-':
if 'r' in mode:
return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
else:
return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
else:
return open(path, mode, buffering)
def crc32c(data, crc=0):
crc ^= 0xffffffff
for b in data:
crc ^= b
for j in range(8):
crc = (crc >> 1) ^ ((crc & 1) * 0x82f63b78)
return 0xffffffff ^ crc
def main(paths, **args):
# interpret as sequence of hex bytes
if args.get('hex'):
bytes_ = [b for path in paths for b in path.split()]
print('%08x' % crc32c(bytes(int(b, 16) for b in bytes_)))
# interpret as strings
elif args.get('string'):
for path in paths:
print('%08x' % crc32c(path.encode('utf8')))
# default to interpreting as paths
else:
if not paths:
paths = [None]
for path in paths:
with openio(path or '-', 'rb') as f:
# calculate crc
crc = 0
while True:
block = f.read(io.DEFAULT_BUFFER_SIZE)
if not block:
break
crc = crc32c(block, crc)
# print what we found
if path is not None:
print('%08x %s' % (crc, path))
else:
print('%08x' % crc)
if __name__ == "__main__":
import argparse
import sys
parser = argparse.ArgumentParser(
description="Calculates crc32cs.",
allow_abbrev=False)
parser.add_argument(
'paths',
nargs='*',
help="Paths to read. Reads stdin by default.")
parser.add_argument(
'-x', '--hex',
action='store_true',
help="Interpret as a sequence of hex bytes.")
parser.add_argument(
'-s', '--string',
action='store_true',
help="Interpret as strings.")
sys.exit(main(**{k: v
for k, v in vars(parser.parse_intermixed_args()).items()
if v is not None}))