rtsubrs.c

早期freebsd实现

/*
 * This source code is a product of Sun Microsystems, Inc. and is provided
 * for unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify this source code without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * THIS PROGRAM CONTAINS SOURCE CODE COPYRIGHTED BY SUN MICROSYSTEMS, INC.
 * SUN MICROSYSTEMS, INC., MAKES NO REPRESENTATIONS ABOUT THE SUITABLITY
 * OF SUCH SOURCE CODE FOR ANY PURPOSE.  IT IS PROVIDED "AS IS" WITHOUT
 * EXPRESS OR IMPLIED WARRANTY OF ANY KIND.  SUN MICROSYSTEMS, INC. DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO SUCH SOURCE CODE, INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN
 * NO EVENT SHALL SUN MICROSYSTEMS, INC. BE LIABLE FOR ANY SPECIAL, INDIRECT,
 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM USE OF SUCH SOURCE CODE, REGARDLESS OF THE THEORY OF LIABILITY.
 * 
 * This source code is provided with no support and without any obligation on
 * the part of Sun Microsystems, Inc. to assist in its use, correction, 
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS
 * SOURCE CODE OR ANY PART THEREOF.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California 94043
 */

/* @(#)rtsubrs.c 1.6 69/12/31 SMI */

/*
 * Copyright (c) 1987, 1991 by Sun Microsystems, Inc.
 */

/*
 * Subroutines for the run-time link editor.
 */

#include <varargs.h>
#include <sys/types.h>

/*
 * Local "printf" & stdio facilities.
 */

int	stdout = 1;			/* File descriptor for output */
int	stderr = 2;			/* File descriptor for errors */

static char *printn();
static void prf();
static void doprf();
static int _write();

/*
 * Indicate whether or not only secure objects should be processed.
 * We indicate "insecure objects" iff the real and effective user and group
 * id's of this process match.  
 */
secure_objects()
{
	static int running_setuid = -1;
	int ruid, euid, rgid, egid;

	if (running_setuid == -1) {
		getreuid(&ruid, &euid);
		getregid(&rgid, &egid);
		running_setuid = (rgid != egid) || (ruid != euid);
	}
	return (running_setuid);
}

/*
 * printf
 */
/*VARARGS1*/
printf(fmt, va_alist)
	char *fmt;
	va_dcl
{
	va_list x1;

	va_start(x1);
	prf(stdout, fmt, x1);
	va_end(x1);
}

/*
 * fprintf
 */
/*VARARGS2*/
fprintf(fd, fmt, va_alist)
	int fd;
	char *fmt;
	va_dcl
{
	va_list x1;

	va_start(x1);
	prf(fd, fmt, x1);
	va_end(x1);
}

/*
 * panic
 */
/*VARARGS2*/
panic(fmt, va_alist)
	char *fmt;
	va_dcl
{
	va_list x1;

	va_start(x1);
	prf(stderr, fmt, x1);
	va_end(x1);
	_exit(127);
	/* NOTREACHED */
}

/*
 * sprintf
 */
/*VARARGS2*/
sprintf(cp, fmt, va_alist)
	char *cp;
	char *fmt;
	va_dcl
{
	va_list x1;

	va_start(x1);
	doprf(-1, fmt, x1, cp);
	va_end(x1);
}

/*
 * printf worker functions
 */
static void
prf(fd, fmt, adx)
	int fd;
	char *fmt;
	va_list adx;
{
	char linebuf[128];

	doprf(fd, fmt, adx, linebuf);
}

static void
doprf(fd, fmt, adx, linebuf)
	int fd;
	register char *fmt;
	register va_list adx;
	char *linebuf;
{
	register int c;			/* Character temporary */
	register char *lbp;		/* Pointer into stack buffer */
	register char *s;		/* %s temporary */
	int i;				/* General integer temporary */
	int b;				/* Conversion base */

#define	PUTCHAR(c)	{\
			if (lbp >= &linebuf[128]) {\
				_write(fd, linebuf, lbp - &linebuf[0]);\
				lbp = &linebuf[0];\
			}\
			*lbp++ = (c);\
			}

	lbp = &linebuf[0];
loop:
	while ((c = *fmt++) != '%') {
		if (c == '\0') {
			_write(fd, linebuf, lbp - &linebuf[0]);
			return;
		}
		PUTCHAR(c);
	}
again:
	c = *fmt++;
	/* THIS CODE IS VAX DEPENDENT IN HANDLING %l? AND %c */
	switch (c) {

	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:
		lbp = printn(fd, va_arg(adx, u_long), b, &linebuf[0], lbp,
		    &linebuf[128]);
		break;

	case 'c':
		b = va_arg(adx, int);
		for (i = 24; i >= 0; i -= 8)
			if (c = (b >> i) & 0x7f) {
				PUTCHAR(c);
			}
		break;

	case 's':
		s = va_arg(adx, char*);
		while (c = *s++) {
			PUTCHAR(c);
		}
		break;

	case '%':
		PUTCHAR('%');
		break;
	}
	goto loop;
}

/*
 * Printn prints a number n in base b.
 */
static char *
printn(fd, n, b, linebufp, lbp, linebufend)
	int fd;				/* File descriptor to get output */
	u_long n;			/* Number */
	int b;				/* Base */
	char *linebufp;			/* Buffer location */
	register char *lbp;		/* Current offset in buffer */
	char *linebufend;		/* Where buffer ends */
{
	char prbuf[11];			/* Local result accumulator */
	register char *cp;

#undef PUTCHAR
#define	PUTCHAR(c)	{\
			if (lbp >= linebufend) {\
				_write(fd, linebufp, lbp - linebufp);\
				lbp = linebufp;\
			}\
			*lbp++ = (c);\
			}

	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);
	return (lbp);
}

static int
_write(fd, buf, len)
	int fd;
	char *buf;
	int len;
{

	if (fd == -1) {
		*(buf + len) = '\0';
		return (0);
	}
	return (write(fd, buf, len));
}