shlex.split()以单个字符串的形式返回整个命令

Question

shlex.split()没有在输入字符串上提供正确的输出。

在python解释器中，将输入值存储在变量中会产生预期的输出。

但是，如果我通过脚本执行，shlex.split()输出是不正确的，并且输入字符串没有在空格上拆分。

>>> import shlex

>>> var = "/usr/bin/ansible-playbook --timeout=60 --module-path /var/sandeep> /playbooks/ --extra-vars '{ \"text\": \"DUMMY\", \"addition\": [\"1\", \"2\", \"3\", ], \"deletion\": [], \"update\": \"update\", \"path\": \"/var/sandeep\", }' /tmp/sandeep//tmp/example.yaml"
>>>
>>>
>>> shlex.split(var)

['/usr/bin/ansible-playbook', '--timeout=60', '--module-path', '/var/sandeep/playbooks/', '--extra-vars', '{ "text": "DUMMY", "addition": ["1", "2", "3", ], "deletion": [], "update": "update", "path": "/var/sandeep", }', '/tmp/sandeep//tmp/example.yaml']

def create_extra(text, extra_dict):
    extra = "'{{ \\\"text\\\": \\\"{}\\\", ".format(text)
    for key, value in extra_dict.items():
        if isinstance(value, list):
            extra += '\\\"{}\\\": ['.format(key)
            for item in value:
                extra += '\\\"{}\\\", '.format(item)
            extra += '], '
        elif isinstance(value, dict):
            extra += '\\\"{}\\\": {{'.format(key)
            for item_key, item_value in value.items():
                extra += '\\\"{}\\\": \\\"{}\\\", '.format(item_key, item_value)
            extra += "}, "
        else:
            extra += '\\\"{}\\\": \\\"{}\\\", '.format(key, value)
    extra += "}'"
    #print("extra: %s" % extra)
    return extra

extra_dict = {'addition': ["1", "2", "3"],
                   'deletion': [],
                   'update': 'update',
                   'path' : '/var/sandeep'
                  }


temp = create_extra("DUMMY", extra_dict)

"""create_extra function formats and return string"""

cmd = ('"/usr/bin/ansible-playbook ' +
        '--timeout=60 '  +
        '--module-path /var/sandeep/playbooks/ ' +
        '--extra-vars {} {}/{}"'.format(temp, "/tmp/sandeep", "/tmp/example.yaml"))

print(cmd)
print(shlex.split(cmd))

output of print(cmd)
"/usr/bin/ansible-playbook --timeout=60 --module-path /var/sandeep/playbooks/ --extra-vars '{ \"text\": \"DUMMY\", \"addition\": [\"1\", \"2\", \"3\", ], \"deletion\": [], \"update\": \"update\", \"path\": \"/var/sandeep\", }' /tmp/sandeep//tmp/example.yaml"


Expected results:
['/usr/bin/ansible-playbook', '--timeout=60', '--module-path', '/var/sandeep/playbooks/', '--extra-vars', '{ "text": "DUMMY", "addition": ["1", "2", "3", ], "deletion": [], "update": "update", "path": "/var/sandeep", }', '/tmp/sandeep//tmp/example.yaml']


Actual Results:
['/usr/bin/ansible-playbook --timeout=60 --module-path /var/sandeep/playbooks/ --extra-vars \'{ "text": "DUMMY", "addition": ["1", "2", "3", ], "deletion": [], "update": "update", "path": "/var/sandeep", }\' /tmp/sandeep//tmp/example.yaml']

我是不是漏掉了什么？

Answer 1

shlex输出是完全正确的，因为字符串中包含文字"字符。

cmd = ('"/usr/bin/ansible-playbook ' +
#       ^- that right there
        '--timeout=60 '  +
        '--module-path /var/sandeep/playbooks/ ' +
        '--extra-vars {} {}/{}"'.format(temp, "/tmp/sandeep", "/tmp/example.yaml"))
#        and this right here -^

因此，正如您的print(cmd)所示：

"/usr/bin/ansible-playbook --timeout=60 --module-path /var/sandeep/playbooks/ --extra-vars whatever /tmp/sandeep//tmp/example.yaml"

...your字符串以"开头，以"结尾，这使得它在被shell解析时成为一个单一的文字字符串。

只要把这些角色去掉，问题就不再发生了：

cmd = ('/usr/bin/ansible-playbook ' +
       '--timeout=60 '  +
       '--module-path /var/sandeep/playbooks/ ' +
       '--extra-vars {} {}/{}'.format(temp, "/tmp/sandeep", "/tmp/example.yaml"))

print(cmd)
print(shlex.split(cmd))

但是，您还有其他严重的错误，因为字符串连接本质上不适合构建命令行。与其尝试采用这种方法，不如直接构建一个数组：

cmd = ['/usr/bin/ansible-playbook',
       '--timeout=60',
       '--module-path', '/var/sandeep/playbooks/',
       '--extra-vars', temp, os.path.join('/tmp/sandeep', '/tmp/example.yml')]

然后，...and中带有空格或文字引号的temp或其他变量的值将不再破坏您的代码或允许注入任意参数。