On 2017-10-06 17:01, eryk sun wrote:
> On Fri, Oct 6, 2017 at 1:31 PM, Thomas Jollans <t...@tjol.eu> wrote:
>> On 2017-10-06 12:33, Ben Bacarisse wrote:
>>
>>> A general solution to the (rather odd) complaint about silent waiting
>>> should really check any input fileno to see if a prompt is needed. You
>>> could argue, though, that anyone who's re-arranged a program's input so
>>> that some non-zero input fileno is attached to a terminal won't need the
>>> prompt!
>>
>> stdin is ALWAYS fileno 0, whether the input is attached to a tty or not.
>> The only situation where sys.stdin.fileno() != 0 is when sys.stdin has
>> been reassigned from within python.
>>
>> $ python -c 'import sys; print(sys.stdin.fileno())' < /dev/zero
>> 0
>>
>> This should be true for all platforms, or at least all platforms python
>> supports.
>
> POSIX defines STDIN_FILENO as 0, and the Windows C runtime reserves FD
> 0 to map to the native StandardInput handle. But as I noted in a
> previous message, on Windows isatty(0) returns true if a process isn't
> executed with a valid StandardInput. In this case sys.stdin will be
> None, so call sys.stdin.fileno() and handle the exception if that
> fails.
Seriously? sys.stdin can be None? That's terrifying.
>
> If you really need to know that stdin is interactive for something
> critical, then isatty() is the wrong function on Windows. You need to
> check for a console, which is most easily done by using ctypes to call
> GetConsoleMode. For example:
>
> import os
>
> if os.name == 'posix':
> from os import isatty
>
> elif os.name == 'nt':
> import ctypes
> import msvcrt
> kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)
>
> def isatty(fd):
> """Return True if the fd is connected to a console."""
> try:
> handle = ctypes.c_void_p(msvcrt.get_osfhandle(fd))
> except (OSError, IOError):
> return False
> mode = ctypes.c_ulong()
> success = kernel32.GetConsoleMode(handle, ctypes.byref(mode))
> return bool(success)
>
--
https://mail.python.org/mailman/listinfo/python-list
