extract_json.py

#!/usr/bin/env python3
# Copyright 2018 The Dawn & Tint Authors
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
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# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
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# 3. Neither the name of the copyright holder nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import os, sys, json

if __name__ == "__main__":
    if len(sys.argv) != 3:
        print("Usage: extract_json.py JSON DIR")
        sys.exit(1)

    with open(sys.argv[1]) as f:
        files = json.loads(f.read())

    output_dir = sys.argv[2]

    for (name, content) in files.items():
        output_file = output_dir + os.path.sep + name

        # Create the output directory if needed.
        directory = os.path.dirname(output_file)
        if not os.path.exists(directory):
            os.makedirs(directory)

        # Skip writing to the file if it already has the correct content.
        try:
            with open(output_file, 'r') as outfile:
                if outfile.read() == content:
                    continue
        except (OSError, EnvironmentError):
            pass

        with open(output_file, 'w') as outfile:
            outfile.write(content)