Ctrl-Z handling on stdin read

[tech...@gmail.com]

Hi,

https://go-review.googlesource.com/#/c/4310/ has a fix for the issue that

it is impossible to end input from stdin in Go programs (like in Python etc).

I wonder what keeps this PR from being reviewed? And how the PR avoids

premature exit when files with Ctrl-Z character are piped into it?

[Benjamin Measures]

On Tuesday, 17 March 2015 16:24:49 UTC, tech...@gmail.com wrote:

I wonder what keeps this PR from being reviewed?

There was a disagreement as to where it should be handled:

• to patch syscall.ReadConsole for a different underlying syscall <https://codereview.appspot.com/45150045>; or
• to patch os.readConsole to handle ctl-z as EOF <https://codereview.appspot.com/95780046>.

afaict both approaches seemed to have issues.

The issue stems from DOS/Windows never producing EOF for console input (it's not a "real" terminal).

[anatoly techtonik]

What is the issue exacly? `copy con xxx.txt` works both in DOS and Windows
for creating multiline files in console, and you terminate the output by sending
CTRL-Z from a blank line. I thought it is EOF.

--
anatoly t.

[Benjamin Measures]

On Tuesday, 17 March 2015 21:45:52 UTC, anatoly techtonik wrote:

On Tue, Mar 17, 2015 at 9:44 PM, Benjamin Measures <saint....@gmail.com> wrote:
> The issue stems from DOS/Windows never producing EOF for console input (it's
> not a "real" terminal).

What is the issue exacly?

In *nix, it is the terminal that signals EOF on ctl-d.

In Windows, there is no console driver. Windows passes the ctl-z to the application, and it is up to the application to interpret however it may. It's an ugly legacy left over from CP/M compat.

[anatoly techtonik]

On Thu, Mar 19, 2015 at 2:14 PM, Benjamin Measures

<saint....@gmail.com> wrote:
> On Tuesday, 17 March 2015 21:45:52 UTC, anatoly techtonik wrote:
>>
>> On Tue, Mar 17, 2015 at 9:44 PM, Benjamin Measures <saint....@gmail.com>
>> wrote:
>> > The issue stems from DOS/Windows never producing EOF for console input
>> > (it's
>> > not a "real" terminal).
>>
>> What is the issue exacly?
>
> In *nix, it is the terminal that signals EOF on ctl-d.
>
> In Windows, there is no console driver. Windows passes the ctl-z to the
> application, and it is up to the application to interpret however it may.
> It's an ugly legacy left over from CP/M compat.

Interesting. How does Windows do this? Is there separate event
handling channel that is different from stdin? Can I create a file and
pipe it to stdin that will end prematurely, because there is encoded
ctrl-z sequence inside?
--
anatoly t.

[Benjamin Measures]

On Thursday, 19 March 2015 14:14:10 UTC, anatoly techtonik wrote:

Can I create a file and pipe it to stdin that will end prematurely, because there is encoded ctrl-z sequence inside?

All About EOF <https://latedev.wordpress.com/2012/12/04/all-about-eof/>:

[...] will create a text file with an embedded Control-Z (ASCII code 26) between the two lines of text. [...] You can now try and read the file using command line facilities. On Windows:

c:\users\neilb\home\temp>type myfile.txt
line 1

Notice only the first line is displayed. On Linux:

[neilb@ophelia temp]$ cat myfile.txt
line 1
?line 2

[tech...@gmail.com]

I'd like to emulate CTRL-Z and CTRL-D handling, because it is a good feature to have. But I don't want it to stand in a way when somebody pipes an actual file to stdin. Is there a way in Go to distinguish when stdin is getting information from file or from keyboard?