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Re: Reading From stdin After Command Line Redirection

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Date Wed, 23 Oct 2013 19:09:36 -0500
From Tim Daneliuk <tundra@tundraware.com>
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Subject Re: Reading From stdin After Command Line Redirection
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On 10/23/2013 05:20 PM, Ben Finney wrote:
> random832@fastmail.us writes:
>
>> On Wed, Oct 23, 2013, at 16:52, Chris Angelico wrote:
>>> There are times when this is correct behaviour - like asking for
>>> passwords (SSH and sudo work like this).
>>
>> Less (or pagers generally, or an interactive text editor that allows
>> creating a file from standard input) would be another example of a
>> program where it makes sense to do this.
>
> You're both describing programs that read the console, which is not what
> the OP was asking for. The OP was asking about re-opening stdin after
> reaching EOF, which is incoherent as far as I understand it.
>
> I'm still waiting for the OP to clarify what they want to do.
>

'Easy there Rainman, the question is entirely coherent,
though it may not be achievable this way.  The goal of the
exercise was:

- Read a file the user specifies via command line redirection
- When the file is fully read, return to reading keyboard
   input with things like raw_input and get_pass which I believe
   use stdin as a source ... probably to avoid having to manually
   cope with ttys and ptys themselves. One of those two functions -
   I don't recall which - was giving me a problem with stdin redirected.

In the end, I broke down and added a command line parameter to
specify which file to read in so that stdin would be unaffected.

Now that I think about it, as I recall from the prehistoric era of writing
lots of assembler and C, if you use shell redirection, stdin shows
up as a handle to the file and there is no way to retrieve/reset it
its default association with the tty/pty.  Since python is layered on
top of this, I expect the same would be the case here as well.



-- 
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Tim Daneliuk     tundra@tundraware.com
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Thread

Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-23 12:25 -0500
  Re: Reading From stdin After Command Line Redirection Chris Angelico <rosuav@gmail.com> - 2013-10-24 07:40 +1100
  Re: Reading From stdin After Command Line Redirection Ben Finney <ben+python@benfinney.id.au> - 2013-10-24 07:46 +1100
  Re: Reading From stdin After Command Line Redirection Chris Angelico <rosuav@gmail.com> - 2013-10-24 07:52 +1100
  Re: Reading From stdin After Command Line Redirection random832@fastmail.us - 2013-10-23 17:01 -0400
  Re: Reading From stdin After Command Line Redirection Ben Finney <ben+python@benfinney.id.au> - 2013-10-24 09:20 +1100
    Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-23 19:09 -0500
      Re: Reading From stdin After Command Line Redirection Ben Finney <ben+python@benfinney.id.au> - 2013-10-24 14:53 +1100
        Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-23 23:36 -0500
        Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-23 23:39 -0500
        Re: Reading From stdin After Command Line Redirection Ben Finney <ben+python@benfinney.id.au> - 2013-10-24 15:54 +1100
          Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-24 06:58 -0500
          Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-24 06:58 -0500
            Re: Reading From stdin After Command Line Redirection Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-24 13:10 +0100
              Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-24 08:41 -0500
                Re: Reading From stdin After Command Line Redirection feedthetroll@gmx.de - 2013-10-24 07:36 -0700
                Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-24 09:43 -0500
              Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-24 08:41 -0500
                Re: Reading From stdin After Command Line Redirection Ethan Furman <ethan@stoneleaf.us> - 2013-10-24 07:30 -0700
      Re: Reading From stdin After Command Line Redirection Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-24 09:14 +0100
      Re: Reading From stdin After Command Line Redirection Ben Finney <ben+python@benfinney.id.au> - 2013-10-24 19:43 +1100
      Re: Reading From stdin After Command Line Redirection Tim Chase <python.list@tim.thechases.com> - 2013-10-24 05:45 -0500
      Re: Reading From stdin After Command Line Redirection Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-24 12:33 +0100
      Re: Reading From stdin After Command Line Redirection Ethan Furman <ethan@stoneleaf.us> - 2013-10-24 07:39 -0700
    Re: Reading From stdin After Command Line Redirection Tim Daneliuk <tundra@tundraware.com> - 2013-10-23 19:09 -0500
  Re: Reading From stdin After Command Line Redirection Chris Angelico <rosuav@gmail.com> - 2013-10-24 09:23 +1100

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