Android 編譯指令碼解析 findleaves.py 解讀
阿新 • • 發佈:2018-11-21
最近在分析Android編譯,加上之前確實寫過關於findleaves.py的應用,今天找時間分析一下原理,也算是學習
#!/usr/bin/env python # # Copyright (C) 2009 The Android Open Source Project # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # # Finds files with the specified name under a particular directory, stopping # the search in a given subdirectory when the file is found. # import os import sys def perform_find(mindepth, prune, dirlist, filename): result = [] //在過濾得列表中找出形如/vendor/android 中android這樣的檔案 pruneleaves = set(map(lambda x: os.path.split(x)[1], prune)) for rootdir in dirlist: rootdepth = rootdir.count("/") for root, dirs, files in os.walk(rootdir, followlinks=True): # prune check_prune = False for d in dirs: if d in pruneleaves: check_prune = True break if check_prune: i = 0 while i < len(dirs): if dirs[i] in prune: del dirs[i] //刪除要過濾掉的目錄名,不去查詢 else: i += 1 # mindepth if mindepth > 0: depth = 1 + root.count("/") - rootdepth if depth < mindepth: continue # match if filename in files: result.append(os.path.join(root, filename)) del dirs[:] return result def usage(): sys.stderr.write("""Usage: %(progName)s [<options>] <dirlist> <filename> Options: --mindepth=<mindepth> Both behave in the same way as their find(1) equivalents. --prune=<dirname> Avoids returning results from inside any directory called <dirname> (e.g., "*/out/*"). May be used multiple times. """ % { "progName": os.path.split(sys.argv[0])[1], }) sys.exit(1) def main(argv): mindepth = -1 prune = [] i=1 //解析對應的引數 while i<len(argv) and len(argv[i])>2 and argv[i][0:2] == "--": arg = argv[i] if arg.startswith("--mindepth="): try: mindepth = int(arg[len("--mindepth="):]) except ValueError: usage() elif arg.startswith("--prune=")://構建要過濾的列表 p = arg[len("--prune="):] if len(p) == 0: usage() prune.append(p) //將新元素新增到列表中 else: usage() i += 1 if len(argv)-i < 2: # need both <dirlist> and <filename> usage() dirlist = argv[i:-1] //我們要找的目錄列表 filename = argv[-1] //我們找找出來的檔案的名稱 results = list(set(perform_find(mindepth, prune, dirlist, filename))) results.sort() for r in results: print r //由此開始執行 if __name__ == "__main__": main(sys.argv)