78 lines
3.0 KiB
Python
78 lines
3.0 KiB
Python
# Copyright 2019, David Wilson
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are met:
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#
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# 1. Redistributions of source code must retain the above copyright notice,
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# this list of conditions and the following disclaimer.
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#
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# 2. Redistributions in binary form must reproduce the above copyright notice,
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# this list of conditions and the following disclaimer in the documentation
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# and/or other materials provided with the distribution.
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#
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# 3. Neither the name of the copyright holder nor the names of its contributors
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# may be used to endorse or promote products derived from this software without
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# specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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# POSSIBILITY OF SUCH DAMAGE.
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from __future__ import absolute_import, division, print_function
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from __future__ import unicode_literals
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__metaclass__ = type
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import mitogen.core
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def parse_script_interpreter(source):
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"""
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Parse the script interpreter portion of a UNIX hashbang using the rules
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Linux uses.
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:param str source: String like "/usr/bin/env python".
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:returns:
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Tuple of `(interpreter, arg)`, where `intepreter` is the script
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interpreter and `arg` is its sole argument if present, otherwise
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:py:data:`None`.
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"""
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# Find terminating newline. Assume last byte of binprm_buf if absent.
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nl = source.find(b'\n', 0, 128)
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if nl == -1:
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nl = min(128, len(source))
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# Split once on the first run of whitespace. If no whitespace exists,
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# bits just contains the interpreter filename.
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bits = source[0:nl].strip().split(None, 1)
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if len(bits) == 1:
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return mitogen.core.to_text(bits[0]), None
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return mitogen.core.to_text(bits[0]), mitogen.core.to_text(bits[1])
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def parse_hashbang(source):
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"""
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Parse a UNIX "hashbang line" using the syntax supported by Linux.
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:param str source: String like "#!/usr/bin/env python".
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:returns:
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Tuple of `(interpreter, arg)`, where `intepreter` is the script
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interpreter and `arg` is its sole argument if present, otherwise
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:py:data:`None`.
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"""
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# Linux requires first 2 bytes with no whitespace, pretty sure it's the
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# same everywhere. See binfmt_script.c.
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if not source.startswith(b'#!'):
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return None, None
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return parse_script_interpreter(source[2:])
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