prf.c

操作系统SunOS 4.1.3版本的源码

/*
 * @(#)prf.c 1.1 92/07/30 Copyright (c) 1985 by Sun Microsystems, Inc.
 */

#include <sys/types.h>
#include <mon/sunromvec.h>

/*
 * Scaled down version of C Library printf.
 * Used to print diagnostic information directly on console tty.
 * Since it is not interrupt driven, all system activities are
 * suspended.  Printf should not be used for chit-chat.
 *
 * One additional format: %b is supported to decode error registers.
 * Usage is:
 *	printf("reg=%b\n", regval, "<base><arg>*");
 * Where <base> is the output base expressed as a control character,
 * e.g. \10 gives octal; \20 gives hex.  Each arg is a sequence of
 * characters, the first of which gives the bit number to be inspected
 * (origin 1), and the next characters (up to a control character, i.e.
 * a character <= 32), give the name of the register.  Thus
 *	printf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
 * would produce output:
 *	reg=2<BITTWO,BITONE>
 */
/*VARARGS1*/
printf(fmt, x1)
	char *fmt;
	unsigned x1;
{

	prf(fmt, &x1);
}

prf(fmt, adx)
	register char *fmt;
	register u_int *adx;
{
	register int b, c, i;
	register char *s;
	register int any;

loop:
	while ((c = *fmt++) != '%') {
		if(c == '\0')
			return;
		putchar(c);
	}
again:
	c = *fmt++;
	switch (c) {

	case 'l':
		goto again;
	case 'x': case 'X':
		b = 16;
		goto number;
	case 'd': case 'D':
	case 'u':		/* what a joke */
		b = 10;
		goto number;
	case 'o': case 'O':
		b = 8;
number:
		printn((u_long)*adx, b);
		break;
	case 'c':
		b = *adx;
		putchar(b);
		break;
	case 'b':
		b = *adx++;
		s = (char *)*adx;
		printn((u_long)b, *s++);
		any = 0;
		if (b) {
			putchar('<');
			while (i = *s++) {
				if (b & (1 << (i-1))) {
					if (any)
						putchar(',');
					any = 1;
					for (; (c = *s) > 32; s++)
						putchar(c);
				} else
					for (; *s > 32; s++)
						;
			}
			putchar('>');
		}
		break;

	case 's':
		s = (char *)*adx;
		while (c = *s++)
			putchar(c);
		break;
	}
	adx++;
	goto loop;
}

/*
 * Printn prints a number n in base b.
 * We don't use recursion to avoid deep kernel stacks.
 */
printn(n, b)
	register u_long n;
	register short b;
{
	char prbuf[11];
	register char *cp;

	if (b == 10 && (int)n < 0) {
		putchar('-');
		n = (unsigned)(-(int)n);
	}
	cp = prbuf;
	do {
		*cp++ = "0123456789abcdef"[n%b];
		n /= b;
	} while (n);
	do
		putchar(*--cp);
	while (cp > prbuf);
}

/*
 * Print a character on console.
 */
putchar(c)
	int c;
{

	(*romp->v_putchar)(c);
}