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From: alex@CS.UCLA.EDU
Newsgroups: comp.lang.c
Subject: Re: HELP!! (Reading one character)
Message-ID: <9176@shemp.UCLA.EDU>
Date: Fri, 13-Nov-87 05:58:04 EST
Article-I.D.: shemp.9176
Posted: Fri Nov 13 05:58:04 1987
Date-Received: Sun, 15-Nov-87 11:11:10 EST
References: <10318@brl-adm.ARPA>
Sender: root@CS.UCLA.EDU
Reply-To: alex@CS.UCLA.EDU (Alex Quilici)
Organization: UCLA Artificial Intelligence Lab
Lines: 43
Summary: Turbo C

In article <10318@brl-adm.ARPA> TGMIKEY%CALSTATE.BITNET@wiscvm.wisc.EDU
talks about two ways to read one character from the input without waiting
for a carriage return.  

>
>C provides you two functions for that :
>
>   (1) x = getch(); where x is char x;  This will return a character from the
>       keyboard (without echoing that character) and it does NOT require the
>       user to follow his/her input with a <CR>.
>
>    (2) x = getche(); where x is as above and the difference between this one
>        and the above getch() is that the character will get echoed to the
>        user as soon as typed.


The problem?  These aren't standard C functions, they are TURBO C
functions.  And they don't do quite what Mike says.

What they actually do is immediately fetch the next character from the
STANDARD INPUT -- not the keyboard.  To really read a character from
the keyboard in Turbo C, use the DOS-BIOS system call bioskey:

  #include <bioskey.h>

  int getkey(void)  /* read next character from KEYBOARD, no echo */
  {
    return (unsigned char) bioskey(0);
  }

  int getkeye(void)  /* getkey + echo character */
  {
     unsigned char key = bioskey(0);
   
     putchar(key);
     return key;
  }

The cast to "unsigned char" throws away the high byte of the
integer bios key returns (information about shift keys and so on
that can often be ignored)

Alex