run_shell_command() - Code Metrics - Inspection of "Better mocking" - coala-analyzer/coala - Measure and Improve Code Quality continuously with Scrutinizer

Failed Conditions

Pull Request — master (#2076)

by Abdeali

created 2016-04-26 07:53 UTC

run_shell_command() A

↳ Parent: Project

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Metric	Value
cc	2
dl	0
loc	22
rs	9.2

from contextlib import contextmanager
import shlex
from subprocess import PIPE, Popen

from coalib.parsing.StringProcessing import escape


@contextmanager

def run_interactive_shell_command(command, **kwargs):
    """
    Runs a single command in shell and provides stdout, stderr and stdin
    streams.

    This function creates a context manager that sets up the process (using
    ``subprocess.Popen()``), returns to caller and waits for process to exit on
    leaving.

    By default the process is opened in ``universal_newlines`` mode and creates
    pipes for all streams (stdout, stderr and stdin) using ``subprocess.PIPE``
    special value. These pipes are closed automatically, so if you want to get
    the contents of the streams you should retrieve them before the context
    manager exits.

    >>> with run_interactive_shell_command(["echo", "TEXT"]) as p:
    ...     stdout = p.stdout
    ...     stdout_text = stdout.read()
    >>> stdout_text
    'TEXT\\n'
    >>> stdout.closed
    True

    Custom streams provided are not closed except of ``subprocess.PIPE``.

    >>> from tempfile import TemporaryFile
    >>> stream = TemporaryFile()
    >>> with run_interactive_shell_command(["echo", "TEXT"],
    ...                                    stdout=stream) as p:
    ...     stderr = p.stderr
    >>> stderr.closed
    True
    >>> stream.closed
    False

    :param command: The command to run on shell. This parameter can either
                    be a sequence of arguments that are directly passed to
                    the process or a string. A string gets splitted beforehand
                    using ``shlex.split()``. If providing ``shell=True`` as a
                    keyword-argument, no ``shlex.split()`` is performed and the
                    command string goes directly to ``subprocess.Popen()``.
    :param kwargs:  Additional keyword arguments to pass to
                    ``subprocess.Popen`` that are used to spawn the process.
    :return:        A context manager yielding the process started from the
                    command.
    """
    if not kwargs.get("shell", False) and isinstance(command, str):

        command = shlex.split(command)

    args = {"stdout": PIPE,

            "stderr": PIPE,
            "stdin": PIPE,
            "universal_newlines": True}
    args.update(kwargs)


    process = Popen(command, **args)
    try:
        yield process
    finally:
        if args["stdout"] is PIPE:
            process.stdout.close()
        if args["stderr"] is PIPE:
            process.stderr.close()
        if args["stdin"] is PIPE:
            process.stdin.close()

        process.wait()


def run_shell_command(command, stdin=None, **kwargs):
    """
    Runs a single command in shell and returns the read stdout and stderr data.

    This function waits for the process (created using ``subprocess.Popen()``)
    to exit. Effectively it wraps ``run_interactive_shell_command()`` and uses
    ``communicate()`` on the process.

    See also ``run_interactive_shell_command()``.

    :param command: The command to run on shell. This parameter can either
                    be a sequence of arguments that are directly passed to
                    the process or a string. A string gets splitted beforehand
                    using ``shlex.split()``.
    :param stdin:   Initial input to send to the process.
    :param kwargs:  Additional keyword arguments to pass to
                    ``subprocess.Popen`` that is used to spawn the process.
    :return:        A tuple with ``(stdoutstring, stderrstring)``.
    """
    with run_interactive_shell_command(command, **kwargs) as p:

        ret = p.communicate(stdin)
    return ret


def get_shell_type():  # pragma: no cover
    """
    Finds the current shell type based on the outputs of common pre-defined
    variables in them. This is useful to identify which sort of escaping
    is required for strings.

    :return: The shell type. This can be either "powershell" if Windows
             Powershell is detected, "cmd" if command prompt is been
             detected or "sh" if it's neither of these.
    """
    out = run_shell_command("echo $host.name", shell=True)[0]
    if out.strip() == "ConsoleHost":
        return "powershell"
    out = run_shell_command("echo $0", shell=True)[0]
    if out.strip() == "$0":
        return "cmd"
    return "sh"


def prepare_string_argument(string, shell=get_shell_type()):
    """
    Prepares a string argument for being passed as a parameter on shell.

    On ``sh`` this function effectively encloses the given string
    with quotes (either '' or "", depending on content).

    :param string: The string to prepare for shell.
    :param shell:  The shell platform to prepare string argument for.
                   If it is not "sh" it will be ignored and return the
                   given string without modification.
    :return:       The shell-prepared string.
    """
    if shell == "sh":
        return '"' + escape(string, '"') + '"'
    else:
        return string


def escape_path_argument(path, shell=get_shell_type()):
    """
    Makes a raw path ready for using as parameter in a shell command (escapes
    illegal characters, surrounds with quotes etc.).

    :param path:  The path to make ready for shell.
    :param shell: The shell platform to escape the path argument for. Possible
                  values are "sh", "powershell", and "cmd" (others will be
                  ignored and return the given path without modification).
    :return:      The escaped path argument.
    """
    if shell == "cmd":
        # If a quote (") occurs in path (which is illegal for NTFS file
        # systems, but maybe for others), escape it by preceding it with
        # a caret (^).
        return '"' + escape(path, '"', '^') + '"'
    elif shell == "sh":
        return escape(path, " ")
    else:
        # Any other non-supported system doesn't get a path escape.
        return path


1			from contextlib import contextmanager
2			import shlex
3			from subprocess import PIPE, Popen
4
5			from coalib.parsing.StringProcessing import escape
6
7
8			@contextmanager
			0 ignored issues – show Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `contextmanager` does not seem to be defined. Loading history...
9			def run_interactive_shell_command(command, **kwargs):
10			"""
11			Runs a single command in shell and provides stdout, stderr and stdin
12			streams.
13
14			This function creates a context manager that sets up the process (using
15			``subprocess.Popen()``), returns to caller and waits for process to exit on
16			leaving.
17
18			By default the process is opened in ``universal_newlines`` mode and creates
19			pipes for all streams (stdout, stderr and stdin) using ``subprocess.PIPE``
20			special value. These pipes are closed automatically, so if you want to get
21			the contents of the streams you should retrieve them before the context
22			manager exits.
23
24			>>> with run_interactive_shell_command(["echo", "TEXT"]) as p:
25			... stdout = p.stdout
26			... stdout_text = stdout.read()
27			>>> stdout_text
28			'TEXT\\n'
29			>>> stdout.closed
30			True
31
32			Custom streams provided are not closed except of ``subprocess.PIPE``.
33
34			>>> from tempfile import TemporaryFile
35			>>> stream = TemporaryFile()
36			>>> with run_interactive_shell_command(["echo", "TEXT"],
37			... stdout=stream) as p:
38			... stderr = p.stderr
39			>>> stderr.closed
40			True
41			>>> stream.closed
42			False
43
44			:param command: The command to run on shell. This parameter can either
45			be a sequence of arguments that are directly passed to
46			the process or a string. A string gets splitted beforehand
47			using ``shlex.split()``. If providing ``shell=True`` as a
48			keyword-argument, no ``shlex.split()`` is performed and the
49			command string goes directly to ``subprocess.Popen()``.
50			:param kwargs: Additional keyword arguments to pass to
51			``subprocess.Popen`` that are used to spawn the process.
52			:return: A context manager yielding the process started from the
53			command.
54			"""
55			if not kwargs.get("shell", False) and isinstance(command, str):
			0 ignored issues – show Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `str` does not seem to be defined. Loading history...
56			command = shlex.split(command)
57
58			args = {"stdout": PIPE,
			0 ignored issues – show Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `PIPE` does not seem to be defined. Loading history...
59			"stderr": PIPE,
60			"stdin": PIPE,
61			"universal_newlines": True}
62			args.update(kwargs)
			0 ignored issues – show Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `kwargs` does not seem to be defined. Loading history...
63
64			process = Popen(command, **args)
65			try:
66			yield process
67			finally:
68			if args["stdout"] is PIPE:
69			process.stdout.close()
70			if args["stderr"] is PIPE:
71			process.stderr.close()
72			if args["stdin"] is PIPE:
73			process.stdin.close()
74
75			process.wait()
76
77
78			def run_shell_command(command, stdin=None, **kwargs):
79			"""
80			Runs a single command in shell and returns the read stdout and stderr data.
81
82			This function waits for the process (created using ``subprocess.Popen()``)
83			to exit. Effectively it wraps ``run_interactive_shell_command()`` and uses
84			``communicate()`` on the process.
85
86			See also ``run_interactive_shell_command()``.
87
88			:param command: The command to run on shell. This parameter can either
89			be a sequence of arguments that are directly passed to
90			the process or a string. A string gets splitted beforehand
91			using ``shlex.split()``.
92			:param stdin: Initial input to send to the process.
93			:param kwargs: Additional keyword arguments to pass to
94			``subprocess.Popen`` that is used to spawn the process.
95			:return: A tuple with ``(stdoutstring, stderrstring)``.
96			"""
97			with run_interactive_shell_command(command, **kwargs) as p:
			0 ignored issues – show Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `p` does not seem to be defined. Loading history... Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `command` does not seem to be defined. Loading history... Comprehensibility Best Practice introduced 2016-04-26 06:36 UTC by Report Bug Copy Issue Report The variable `kwargs` does not seem to be defined. Loading history...
98			ret = p.communicate(stdin)
99			return ret
100
101
102			def get_shell_type(): # pragma: no cover
103			"""
104			Finds the current shell type based on the outputs of common pre-defined
105			variables in them. This is useful to identify which sort of escaping
106			is required for strings.
107
108			:return: The shell type. This can be either "powershell" if Windows
109			Powershell is detected, "cmd" if command prompt is been
110			detected or "sh" if it's neither of these.
111			"""
112			out = run_shell_command("echo $host.name", shell=True)[0]
113			if out.strip() == "ConsoleHost":
114			return "powershell"
115			out = run_shell_command("echo $0", shell=True)[0]
116			if out.strip() == "$0":
117			return "cmd"
118			return "sh"
119
120
121			def prepare_string_argument(string, shell=get_shell_type()):
122			"""
123			Prepares a string argument for being passed as a parameter on shell.
124
125			On ``sh`` this function effectively encloses the given string
126			with quotes (either '' or "", depending on content).
127
128			:param string: The string to prepare for shell.
129			:param shell: The shell platform to prepare string argument for.
130			If it is not "sh" it will be ignored and return the
131			given string without modification.
132			:return: The shell-prepared string.
133			"""
134			if shell == "sh":
135			return '"' + escape(string, '"') + '"'
136			else:
137			return string
138
139
140			def escape_path_argument(path, shell=get_shell_type()):
141			"""
142			Makes a raw path ready for using as parameter in a shell command (escapes
143			illegal characters, surrounds with quotes etc.).
144
145			:param path: The path to make ready for shell.
146			:param shell: The shell platform to escape the path argument for. Possible
147			values are "sh", "powershell", and "cmd" (others will be
148			ignored and return the given path without modification).
149			:return: The escaped path argument.
150			"""
151			if shell == "cmd":
152			# If a quote (") occurs in path (which is illegal for NTFS file
153			# systems, but maybe for others), escape it by preceding it with
154			# a caret (^).
155			return '"' + escape(path, '"', '^') + '"'
156			elif shell == "sh":
157			return escape(path, " ")
158			else:
159			# Any other non-supported system doesn't get a path escape.
160			return path
161

coala-analyzer / coala

Pull Request — master (#2076)

run_shell_command() A

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