ascii.c

cc65 的编译器文档

/* ascii.c
**
** Shows the ASCII (or ATASCII, PETSCII) codes of typed characters.
**
** 2003-03-09, Greg King <[e-mail]>
*/

/* Define USE_STDIO, when you want to use the stdio functions.
** Do not define it, when you want to use the conio functions.
** NOTE:  stdin on some targets is line-bufferred.  You might need to type
**        a key, then tap the return(enter)-key, in order to see each code.
*/
/*
#define USE_STDIO
*/

#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#define QUIT	'Q'

/* r -- row.  t -- table-column.
*/
static unsigned char height, width, r, t;
static int c;

#ifndef USE_STDIO

# define PRINT	cprintf
# define PUT(c)	cputc((char)(c))

/* conio doesn't echo typed characters.
** So, this function does it.
*/
static int GET(void) {
	PUT(c = (int)cgetc());
	return c;
	}

#else

# define PRINT	printf
# define GET	getchar

#endif

int main(void) {

#	ifndef USE_STDIO
	/* conio doesn't scroll!  Avoid trouble by starting at the top
	** of the screen, and never going "below" the bottom of the screen.
	*/
	clrscr();
	r = 7;				/* allow for prompt */
#	endif

	/* This prompt fits on the VIC-20's narrow screen.
	*/
	PRINT("Type characters to see\r\ntheir hexadecimal code\r\nnumbers:\r\n\n");
	screensize(&width, &height);	/* get the screen's dimensions */
	width /= 6;			/* get number of codes on a line */
	cursor(true);
	t = 0;
	while ((c = GET()) != EOF) {

#		ifndef USE_STDIO
		if (r == height) {
			clrscr();
			t = 0;
			PUT(c);	/* echo char. again because screen was erased */
			r = 1;
			}
		if (c == '\n')
			++r;
#		endif

		PRINT("=$%02x ", c);
		if (c == QUIT)
			break;
		if (++t == width) {
			PRINT("\r\n");
			++r;
			t = 0;
			}
		}
	PRINT("\r\n");
	return EXIT_SUCCESS;
	}