Thread: Read keyb in uninterrupted loop

Hello

I'm looking for a way to input text from the keyboard - whithout having to wait for the user, because I have to do some other checks in the loop.

I've tried with kbhit but that results in the user are forced to perform an extra keypress after she has pressed enter.

But as I understand is using getchar() results in having the loop waiting for input - thus delaying the loop heavily - which means that I have to sniff a bit in the keyb buffer before reading the characters entered by the user. There for I have to some precheck or ????

Code:

while(1)
{
  if (kbhit()!=0)
   {
     if ((c=getchar()) != '\n')
   {
     myString[i]=(char)c;
     i=i+1;
   }
    else
          {
            //Data processing
          }
   }
     //SEND
     //RECEIVE
     // Delay if needed
}

Heelp somebody
I would really appreciate it.

Many regards
Peter

What OS/Compiler are you using?

--
Mats

Ok, so you are probably not using a standard C library either? That makes the whole business a whole lot harder.

Could you use "getch()" instead of getchar()?

[Trivia question: What year was gcc 2.7.2 produced?]

--
Mats

Originally Posted by matsp

[Trivia question: What year was gcc 2.7.2 produced?]

Guess: 1993

That must have been a good one tho, for years you could only compile the linux kernel with 2.7.2

Originally Posted by flywheel

No unfortunately conio.h is not available

But you have a "kbhit()", so look at what "kbhit()", or look a the low-level bits of code dealing with getchar() [but that may be quite hard to find, as there is probably quite a few levels between the call to getchar() and the actual reading of the data], and write a getch() function.

--
Mats

The other obvious solution would be to use two threads.

--
Mats

Originally Posted by flywheel

Threads is also a problem - perhaps I should look into moving this part into a PC-client.
Which means that I would have conio.h at my displosal.

What could I do if I had getch ?

getch() by tradition waits for a single character to be ready, and then goes on. Since you already have kbhit, you can determine when to call getch() without having to wait at all.

--
Mats

Originally Posted by flywheel

But doesn't getchar do the same as getch - it just echoes the character to stdin ?

getchar does not process input till the enter is pressed