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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2020-03-24 21:59:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2020-03-24 21:59:15 +0000 |
commit | 63fad53303381388673073de580a32088a4ef0fe (patch) | |
tree | a2c5c329ee5e79a220fac7e079283235fecc0cda /pre_commit/parse_shebang.py | |
parent | Initial commit. (diff) | |
download | pre-commit-63fad53303381388673073de580a32088a4ef0fe.tar.xz pre-commit-63fad53303381388673073de580a32088a4ef0fe.zip |
Adding upstream version 2.2.0.upstream/2.2.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'pre_commit/parse_shebang.py')
-rw-r--r-- | pre_commit/parse_shebang.py | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/pre_commit/parse_shebang.py b/pre_commit/parse_shebang.py new file mode 100644 index 0000000..d344a1d --- /dev/null +++ b/pre_commit/parse_shebang.py @@ -0,0 +1,84 @@ +import os.path +from typing import Mapping +from typing import Optional +from typing import Tuple +from typing import TYPE_CHECKING + +from identify.identify import parse_shebang_from_file + +if TYPE_CHECKING: + from typing import NoReturn + + +class ExecutableNotFoundError(OSError): + def to_output(self) -> Tuple[int, bytes, None]: + return (1, self.args[0].encode(), None) + + +def parse_filename(filename: str) -> Tuple[str, ...]: + if not os.path.exists(filename): + return () + else: + return parse_shebang_from_file(filename) + + +def find_executable( + exe: str, _environ: Optional[Mapping[str, str]] = None, +) -> Optional[str]: + exe = os.path.normpath(exe) + if os.sep in exe: + return exe + + environ = _environ if _environ is not None else os.environ + + if 'PATHEXT' in environ: + exts = environ['PATHEXT'].split(os.pathsep) + possible_exe_names = tuple(f'{exe}{ext}' for ext in exts) + (exe,) + else: + possible_exe_names = (exe,) + + for path in environ.get('PATH', '').split(os.pathsep): + for possible_exe_name in possible_exe_names: + joined = os.path.join(path, possible_exe_name) + if os.path.isfile(joined) and os.access(joined, os.X_OK): + return joined + else: + return None + + +def normexe(orig: str) -> str: + def _error(msg: str) -> 'NoReturn': + raise ExecutableNotFoundError(f'Executable `{orig}` {msg}') + + if os.sep not in orig and (not os.altsep or os.altsep not in orig): + exe = find_executable(orig) + if exe is None: + _error('not found') + return exe + elif os.path.isdir(orig): + _error('is a directory') + elif not os.path.isfile(orig): + _error('not found') + elif not os.access(orig, os.X_OK): # pragma: win32 no cover + _error('is not executable') + else: + return orig + + +def normalize_cmd(cmd: Tuple[str, ...]) -> Tuple[str, ...]: + """Fixes for the following issues on windows + - https://bugs.python.org/issue8557 + - windows does not parse shebangs + + This function also makes deep-path shebangs work just fine + """ + # Use PATH to determine the executable + exe = normexe(cmd[0]) + + # Figure out the shebang from the resulting command + cmd = parse_filename(exe) + (exe,) + cmd[1:] + + # This could have given us back another bare executable + exe = normexe(cmd[0]) + + return (exe,) + cmd[1:] |