getchar when buffer is empty??

[spike232]

when u use getchar if the buffer is empty then it just sits and waits, is their any way to skip this, or chek the buffer first??

[Prelude]

>is their any way to skip this
Yes, hit a key.

-Prelude

[bigtamscot]

when using getchar, after selecting your character, unless it is return or enter keys, you will have to hit return or enter to before continuing.

getchar();
/* hit key of your choice, then hit return */

you could use <conio.h> if it is available to you and functions getch(); or getche();

[dharh]

I think he might want to something where, if the buffer is empty do nothing. If the buffer has something in it, read it.

[spike232]

Originally posted by dharh
I think he might want to something where, if the buffer is empty do nothing. If the buffer has something in it, read it.

that is what i ment

[quzah]

Originally posted by spike232


that is what i ment

You need the non-ANSI, DOS based function "kbdhit()". You check kbdhit() which returns true if a key has been struck. There is no ANSI way to do this.

Quzah.

[Lynux-Penguin]

could you print us some code so that we may inspect your program closely and determine what it is exactly that you want.

[dharh]

Here is an example of what I use to read stuff from stdin.

/* fgets _stdin function, gets like fgets using _stdin 
*/
int gets_s(char *str, int size) {
      /* variable to say if there has been an error, might change to a pointer
      ** which would return NULL upon error.
      */
  int error;
  int c;      /* a single "character" */
  char *ptr;  /* pointer to first \n in string */

  if (fgets(str, size, stdin) != NULL) {
    if ((ptr = strchr(str, '\n')) != NULL) {
      *ptr = '\0';
      error = 0;
    }
    else {
      while (((c = getchar()) != '\n') && (c != EOF)) {
      }
      error = 1;
    }
  }
  else {
    error = 1;
  }

  return (error);
}

[Unregistered]

Out of intrests what's the difference between the getchar() function and the fucntions getch(); or getche(); in the conio.h?

btw, as said, kbhit() works perfect if in DOS conio.h if u just wanna check if key is waiting, here code showing getting and processing if key has been pressed,

if(kbhit())
{
p = getchar();
while(p == 'L')
{
i = (rand() % 50);
MsgBox(DIE_STRINGS[i]);
p = getch();
}
if(p == UP) overallDir = UP;
if(p == DOWN) overallDir = DOWN;
if(p == LEFT) overallDir = LEFT;
if(p == RIGHT) overallDir = RIGHT;
}

[Hammer]

Originally posted by Unregistered
Out of intrests what's the difference between the getchar() function and the fucntions getch(); or getche(); in the conio.h?

getchar() is ANSI standard, the others are not (or so I believe).

[Unregistered]

I'm not sure about ANSII standards, but getchar() takes a character after you hit enter getch() instantly takes the character (no enter means don't push the wrong key!) and getche() is getch() + screen echo.

getch() is very good for menus in dos and I use it all the time, but, you can run into problems with it.