kbhit.gml

来自「开放源码的编译器open watcom 1.6.0版的源代码」· GML 代码 · 共 53 行

.func kbhit
#include <conio.h>
int kbhit( void );
.ixfunc2 '&KbIo' &func
.funcend
.desc begin
The &func function tests whether or not a keystroke is currently
available.
When one is available, the function
.kw getch
or
.kw getche
may be used to obtain the keystroke in question.
.pp
With a stand-alone program, the &func function may be called
continuously until a keystroke is available.
.if '&machsys' eq 'QNX' .do begin
Note that loops involving the &func function are not recommended in
multitasking systems.
.do end
.desc end
.return begin
The &func
function returns zero when no keystroke is available; otherwise, a
non-zero value is returned.
.return end
.see begin
.im seeiocon kbhit
.see end
.exmp begin
/*
 * This program loops until a key is pressed
 * or a count is exceeded.
 */
#include <stdio.h>
#include <conio.h>

void main()
  {
    unsigned long i;
.exmp break
    printf( "Program looping. Press any key.\n" );
    for( i = 0; i < 10000; i++ ) {
      if( kbhit() ) {
        getch();
        break;
      }
    }
  }
.exmp end
.class WATCOM
.system