Repository: pallets/click
File: src/click/_termui_impl.py (Python)

Code before:
    """
    import subprocess

    env = dict(os.environ)

    # If we're piping to less we might support colors under the
    # condition that
    cmd_detail = cmd.rsplit("/", 1)[-1].split()
    if color is None and cmd_detail[0] == "less":
        less_flags = f"{os.environ.get('LESS', '')}{' '.join(cmd_detail[1:])}"
        if not less_flags:
            env["LESS"] = "-R"
            color = True
        elif "r" in less_flags or "R" in less_flags:
            color = True

    c = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, env=env)
    stdin = t.cast(t.BinaryIO, c.stdin)
    encoding = get_best_encoding(stdin)
    try:
        for text in generator:
            if not color:
                text = strip_ansi(text)

            stdin.write(text.encode(encoding, "replace"))
            stdin.flush()
    except Exception as e:
        # In case there is an exception we want to close the pager immediately
        # and let the caller handle it.
        # Otherwise the pager will keep running, and the user may not notice
        # the error message, or worse yet it may leave the terminal in a broken state.
        c.terminate()
        raise e
    finally:
        # We must close stdin and wait for the pager to exit before we continue
        stdin.close()

        # Less doesn't respect ^C, but catches it for its own UI purposes (aborting
        # search or other commands inside less).
        #
        # That means when the user hits ^C, the parent process (click) terminates,
        # but less is still alive, paging the output and messing up the terminal.
        #
        # If the user wants to make the pager exit on ^C, they should set
        # `LESS='-K'`. It's not our decision to make.
        while True:
            try:
                c.wait()
            except KeyboardInterrupt:
                pass
            else:

Review comment (bug):
Close implies flush, so this one is not necessary. https://stackoverflow.com/questions/2447143/does-close-imply-flush-in-python
```suggestion
```

Code after:
def _pipepager(generator: cabc.Iterable[str], cmd: str, color: bool | None) -> None:
    """Page through text by feeding it to another program.  Invoking a
    pager through this might support colors.
    """
    import subprocess

    env = dict(os.environ)

    # If we're piping to less we might support colors under the
    # condition that
    cmd_detail = cmd.rsplit("/", 1)[-1].split()
    if color is None and cmd_detail[0] == "less":
        less_flags = f"{os.environ.get('LESS', '')}{' '.join(cmd_detail[1:])}"
        if not less_flags:
            env["LESS"] = "-R"
            color = True
        elif "r" in less_flags or "R" in less_flags:
            color = True

    c = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, env=env)
    stdin = t.cast(t.BinaryIO, c.stdin)
    encoding = get_best_encoding(stdin)
    try:
        for text in generator:
            if not color:
                text = strip_ansi(text)

            stdin.write(text.encode(encoding, "replace"))
    except BrokenPipeError:
        # In case the pager exited unexpectedly, ignore the broken pipe error.
        pass
    except Exception as e:
        # In case there is an exception we want to close the pager immediately
        # and let the caller handle it.
        # Otherwise the pager will keep running, and the user may not notice
        # the error message, or worse yet it may leave the terminal in a broken state.
        c.terminate()
        raise e
    finally:
        # We must close stdin and wait for the pager to exit before we continue
        try:
            stdin.close()
        # Close implies flush, so it might throw a BrokenPipeError if the pager
        # process exited already.
        except BrokenPipeError:
            pass

        # Less doesn't respect ^C, but catches it for its own UI purposes (aborting
        # search or other commands inside less).
        #
        # That means when the user hits ^C, the parent process (click) terminates,