pre_commit_hooks/check_shebang_scripts_are_executable.py

"""Check that text files with a shebang are executable."""
import argparse
import shlex
import sys
from typing import List
from typing import Optional
from typing import Sequence
from typing import Set

from pre_commit_hooks.check_executables_have_shebangs import EXECUTABLE_VALUES
from pre_commit_hooks.check_executables_have_shebangs import git_ls_files
from pre_commit_hooks.check_executables_have_shebangs import has_shebang


def check_shebangs(paths: List[str]) -> int:
    # Cannot optimize on non-executability here if we intend this check to
    # work on win32 -- and that's where problems caused by non-executability
    # (elsewhere) are most likely to arise from.
    return _check_git_filemode(paths)


def _check_git_filemode(paths: Sequence[str]) -> int:
    seen: Set[str] = set()
    for ls_file in git_ls_files(paths):
        is_executable = any(b in EXECUTABLE_VALUES for b in ls_file.mode[-3:])
        if not is_executable and has_shebang(ls_file.filename):
            _message(ls_file.filename)
            seen.add(ls_file.filename)

    return int(bool(seen))


def _message(path: str) -> None:
    print(
        f'{path}: has a shebang but is not marked executable!\n'
        f'  If it is supposed to be executable, try: '
        f'`chmod +x {shlex.quote(path)}`\n'
        f'  If it not supposed to be executable, double-check its shebang '
        f'is wanted.\n',
        file=sys.stderr,
    )


def main(argv: Optional[Sequence[str]] = None) -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('filenames', nargs='*')
    args = parser.parse_args(argv)

    return check_shebangs(args.filenames)


if __name__ == '__main__':
    exit(main())