本文主要是介绍subprocess使用方法，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
代码示例：
#!/usr/bin/env pythonimport subprocess
import sysdef print_file_type(file_name):cmd = ['file ' + file_name]p = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE)stdout, stderr = p.communicate()print 'stdout:', stdoutprint 'stderr:', stderrprint 'return code:', p.returncodedef usage(): print sys.argv[0], "file_name"if __name__=="__main__": argc = len(sys.argv) if argc != 2: usage() sys.exit(-1) file_name = sys.argv[1] print_file_type(file_name)
运行示例：
flying-bird@flyingbird:~/examples/python/print_file_type$ ./print_file_type.py ./print_file_type.py
stdout: ./print_file_type.py: Python script, ASCII text executablestderr: None
return code: 0
flying-bird@flyingbird:~/examples/python/print_file_type$ ./print_file_type.py ../../cpp/read_write_read/a.out
stdout: ../../cpp/read_write_read/a.out: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=5520f400b4561a89d9d2b712a8b288ef72411a49, not strippedstderr: None
return code: 0
flying-bird@flyingbird:~/examples/python/print_file_type$ file ./print_file_type.py
./print_file_type.py: Python script, ASCII text executable
flying-bird@flyingbird:~/examples/python/print_file_type$ file ../../cpp/read_write_read/a.out
../../cpp/read_write_read/a.out: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=5520f400b4561a89d9d2b712a8b288ef72411a49, not stripped
flying-bird@flyingbird:~/examples/python/print_file_type$
参考资料：
Android源码的build/tools/releasetools/common.py的如下部分：
def Run(args, **kwargs):"""Create and return a subprocess.Popen object, printing the commandline on the terminal if -v was specified."""if OPTIONS.verbose:print " running: ", " ".join(args)return subprocess.Popen(args, **kwargs)def GetKeyPasswords(keylist):"""Given a list of keys, prompt the user to enter passwords forthose which require them. Return a {key: password} dict. passwordwill be None if the key has no password."""no_passwords = []need_passwords = []key_passwords = {}devnull = open("/dev/null", "w+b")for k in sorted(keylist):# We don't need a password for things that aren't really keys.if k in SPECIAL_CERT_STRINGS:no_passwords.append(k)continuep = Run(["openssl", "pkcs8", "-in", k+OPTIONS.private_key_suffix,"-inform", "DER", "-nocrypt"],stdin=devnull.fileno(),stdout=devnull.fileno(),stderr=subprocess.STDOUT)p.communicate()if p.returncode == 0:# Definitely an unencrypted key.no_passwords.append(k)else:p = Run(["openssl", "pkcs8", "-in", k+OPTIONS.private_key_suffix,"-inform", "DER", "-passin", "pass:"],stdin=devnull.fileno(),stdout=devnull.fileno(),stderr=subprocess.PIPE)stdout, stderr = p.communicate()if p.returncode == 0:# Encrypted key with empty string as password.key_passwords[k] = ''elif stderr.startswith('Error decrypting key'):# Definitely encrypted key.# It would have said "Error reading key" if it didn't parse correctly.need_passwords.append(k)else:# Potentially, a type of key that openssl doesn't understand.# We'll let the routines in signapk.jar handle it.no_passwords.append(k)devnull.close()key_passwords.update(PasswordManager().GetPasswords(need_passwords))key_passwords.update(dict.fromkeys(no_passwords, None))return key_passwords
这篇关于subprocess使用方法的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
