mirror of
https://github.com/jart/cosmopolitan.git
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27 lines
664 B
Python
27 lines
664 B
Python
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from builtins import open as _orig_open
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def open(file, mode='r', bufsize=-1):
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if 'w' not in mode:
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return _orig_open(file, mode, bufsize)
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import os
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backup = file + '~'
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try:
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os.unlink(backup)
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except OSError:
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pass
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try:
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os.rename(file, backup)
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except OSError:
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return _orig_open(file, mode, bufsize)
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f = _orig_open(file, mode, bufsize)
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_orig_close = f.close
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def close():
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_orig_close()
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import filecmp
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if filecmp.cmp(backup, file, shallow=False):
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import os
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os.unlink(file)
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os.rename(backup, file)
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f.close = close
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return f
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