| #!/usr/bin/env python3 |
| # Copyright 2012 The Chromium Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Extracts a single file from a CAB archive.""" |
| |
| |
| import os |
| import shutil |
| import subprocess |
| import sys |
| import tempfile |
| |
| def run_quiet(*args): |
| """Run 'expand' suppressing noisy output. Returns returncode from process.""" |
| popen= subprocess.Popen(args, stdout=subprocess.PIPE) |
| out, _= popen.communicate() |
| if popen.returncode: |
| # expand emits errors to stdout, so if we fail, then print that out. |
| print(out) |
| return popen.returncode |
| |
| def main(): |
| if len(sys.argv)!=4: |
| print('Usage: extract_from_cab.py cab_path archived_file output_dir') |
| return1 |
| |
| [cab_path, archived_file, output_dir]= sys.argv[1:] |
| |
| # Expand.exe does its work in a fixed-named temporary directory created within |
| # the given output directory. This is a problem for concurrent extractions, so |
| # create a unique temp dir within the desired output directory to work around |
| # this limitation. |
| temp_dir= tempfile.mkdtemp(dir=output_dir) |
| |
| try: |
| # Invoke the Windows expand utility to extract the file. |
| level= run_quiet('expand', cab_path,'-F:'+ archived_file, temp_dir) |
| if level==0: |
| # Move the output file into place, preserving expand.exe's behavior of |
| # paving over any preexisting file. |
| output_file= os.path.join(output_dir, archived_file) |
| try: |
| os.remove(output_file) |
| exceptOSError: |
| pass |
| os.rename(os.path.join(temp_dir, archived_file), output_file) |
| finally: |
| shutil.rmtree(temp_dir,True) |
| |
| if level!=0: |
| return level |
| |
| # The expand utility preserves the modification date and time of the archived |
| # file. Touch the extracted file. This helps build systems that compare the |
| # modification times of input and output files to determine whether to do an |
| # action. |
| os.utime(os.path.join(output_dir, archived_file),None) |
| return0 |
| |
| |
| if __name__=='__main__': |
| sys.exit(main()) |
