/*
   =============================================================================
	waitcr.c -- wait for a CR from the console and allow for debugging
	Version 3 -- 1987-07-15 -- D.N. Lynx Crowe
   =============================================================================
*/

#include "biosdefs.h"
#include "stddefs.h"

extern	int	xtrap15();	/* the ROMP trap */

/*
   =============================================================================
	waitcr() -- wait for a CR or a CTL-G.  CR returns control to the
	caller, CTL-G invokes xtrap15(), which if it returns, returns to
	the caller.  The xtrap15() escape is to allow a convenient debug
	point whenever we wait on the console.  The character that caused
	the return  (CR or CTL-G) is returned as the value of the function.
   =============================================================================
*/

int
waitcr()
{
	int	c;

	BIOS(B_PUTC, CON_DEV, '\007');		/* wake up the operator */

	/* await a CR, in which case we just exit */

	while ('\r' NE (c = (0x007F & (int)BIOS(B_GETC, CON_DEV))))
		if (c EQ '\007')	/* ... or a control-G */
			xtrap15();	/* ... in which case we trap first */

	return(c);	/* return the character that caused us to exit */
}