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8687.15.18
by Karl Fogel
Add the copyright header block to files under lib/canonical/. |
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# Copyright 2009 Canonical Ltd. This software is licensed under the
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# GNU Affero General Public License version 3 (see the file LICENSE).
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5294.1.3
by Jeroen Vermeulen
Addressed BjornT's points prior to resuming formal review. |
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"""Helper functions for running external commands."""
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__metaclass__ = type |
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7675.1116.6
by Jeroen Vermeulen
Helper tests, and small fry. |
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__all__ = [ |
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'run_command', |
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'run_script', |
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]
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5294.1.3
by Jeroen Vermeulen
Addressed BjornT's points prior to resuming formal review. |
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import subprocess |
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import sys |
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def run_command(command, args=None, input=None, shell=False): |
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"""Run an external command in a separate process.
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:param command: executable to run.
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:param args: optional list of command-line arguments.
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:param input: optional text to feed to command's standard input.
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:param shell: passed directly to `subprocess.Popen`.
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:return: tuple of return value, standard output, and standard error.
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"""
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command_line = [command] |
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if args: |
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command_line.extend(args) |
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if input is not None: |
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stdin = subprocess.PIPE |
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else: |
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stdin = None |
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child = subprocess.Popen( |
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command_line, stdin=stdin, stdout=subprocess.PIPE, |
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stderr=subprocess.PIPE) |
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stdout, stderr = child.communicate(input) |
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result = child.wait() |
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return (result, stdout, stderr) |
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def run_script(script, args=None, input=None): |
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"""Run a Python script in a child process, using current interpreter.
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:param script: Python script to run.
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:param args: optional list of command-line arguments.
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:param input: optional string to feed to standard input.
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:return: tuple of return value, standard output, and standard error.
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"""
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interpreter_args = [script] |
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if args: |
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interpreter_args.extend(args) |
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return run_command(sys.executable, interpreter_args, input) |