something like kbhit

[DevarajA]

How can i know if there are characters in the standard input using only
standard c++? I want to stop a loop when any key is pressed.

 

[Artie Gold]

How can i know if there are characters in the standard input using only
standard c++? I want to stop a loop when any key is pressed.

You cannot.

HTH,
--ag

 

[rossum]

How can i know if there are characters in the standard input using only
standard c++? I want to stop a loop when any key is pressed.

As Artie said, you can't. Have a look at the FAQ:
http://www.parashift.com/c++-faq-lite/, in particular 15.17.

rossum



The ultimate truth is that there is no ultimate truth

 

[DevarajA]

rossum ha scritto:

As Artie said, you can't. Have a look at the FAQ:
http://www.parashift.com/c++-faq-lite/, in particular 15.17.

rossum



The ultimate truth is that there is no ultimate truth

The faq talks about a keyboard.. and I know that c++ doesnt require a
keyboard, but somewhere there must be an input stream, so I just want to
know if there is even one character on it without stopping the program
(the function looks at the stream, if it's empty returns 0, otherwise it
returns 1). I think this could be possible.

 

[Lionel B]

rossum ha scritto:

The faq talks about a keyboard.. and I know that c++ doesnt require a
keyboard, but somewhere there must be an input stream, so I just want
to know if there is even one character on it without stopping the
program (the function looks at the stream, if it's empty returns 0,
otherwise it returns 1). I think this could be possible.

No, it really, really, really isn't. There are frequently OS-specific libraries that will do what you want, though. Have
you actually looked at the FAQ 15.17?

 

[DevarajA]

Lionel B ha scritto:

No, it really, really, really isn't. There are frequently OS-specific libraries that will do what you want, though. Have
you actually looked at the FAQ 15.17?

Yes but i can't get it working. Anyway i'm already using a non-standard
function that works perfectly, I just wanted to make it standard to
avoid problems when porting.

 

[Lionel B]

Lionel B ha scritto:

Yes but i can't get it working.

What's the problem (I'm assuming you're on a Posix system)? If it's C++ related, why not post it here? Else in a Unix
programmers ng, maybe?

Anyway i'm already using a
non-standard function that works perfectly, I just wanted to make it
standard to avoid problems when porting.

Right... well as I guess you've gathered by now, you're out of luck there. If you can get the Posix solution working
that will at least increase your portability to a lot of systems (and you've already got kbhit and all the conio.h stuff
on Win32... don't know about Mac).

Cheers,

 

[DevarajA]

Lionel B ha scritto:

What's the problem (I'm assuming you're on a Posix system)? If it's C++ related, why not post it here? Else in a Unix
programmers ng, maybe?

the faq tells me to "poll", but i don't know how to poll

 

[Alan Johnson]

Lionel B ha scritto:



the faq tells me to "poll", but i don't know how to poll

select()
http://www.opengroup.org/onlinepubs/009695399/functions/select.html

poll()
http://www.opengroup.org/onlinepubs/009695399/functions/poll.html

select and poll serve essentially the same purpose. select is a bit
easier to use, in my opinion. poll is probably a bit more efficient on
most systems (though if you are just monitoring stdin that won't matter).

-Alan