464 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			464 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 1989, 1993, 1994
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|  *	The Regents of the University of California.  All rights reserved.
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|  *
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|  * This code is derived from software contributed to Berkeley by
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|  * Dave Borman at Cray Research, Inc.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  * 3. All advertising materials mentioning features or use of this software
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|  *    must display the following acknowledgement:
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|  *	This product includes software developed by the University of
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|  *	California, Berkeley and its contributors.
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|  * 4. Neither the name of the University nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #if defined(LIBC_SCCS) && !defined(lint)
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| static char sccsid[] = "@(#)setmode.c	8.2 (Berkeley) 3/25/94";
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| #endif /* LIBC_SCCS and not lint */
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| 
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| #include <sys/types.h>
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| #include <sys/stat.h>
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| 
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| #include <ctype.h>
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| #include <errno.h>
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| #include <signal.h>
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| #include <stddef.h>
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| #include <stdlib.h>
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| 
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| #ifdef SETMODE_DEBUG
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| #include <stdio.h>
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| #endif
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| 
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| #include "shell.h"
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| 
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| #ifndef S_ISTXT
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| #define S_ISTXT	S_ISVTX
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| #endif
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| 
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| #define	SET_LEN	6		/* initial # of bitcmd struct to malloc */
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| #define	SET_LEN_INCR 4		/* # of bitcmd structs to add as needed */
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| 
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| typedef struct bitcmd {
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| 	char	cmd;
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| 	char	cmd2;
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| 	mode_t	bits;
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| } BITCMD;
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| 
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| #define	CMD2_CLR	0x01
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| #define	CMD2_SET	0x02
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| #define	CMD2_GBITS	0x04
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| #define	CMD2_OBITS	0x08
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| #define	CMD2_UBITS	0x10
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| 
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| static BITCMD	*addcmd (BITCMD *, int, int, int, unsigned int);
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| static void	 compress_mode (BITCMD *);
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| #ifdef SETMODE_DEBUG
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| static void	 dumpmode __P((BITCMD *));
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| #endif
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| 
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| /*
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|  * Given the old mode and an array of bitcmd structures, apply the operations
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|  * described in the bitcmd structures to the old mode, and return the new mode.
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|  * Note that there is no '=' command; a strict assignment is just a '-' (clear
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|  * bits) followed by a '+' (set bits).
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|  */
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| mode_t
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| getmode(bbox, omode)
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| 	void *bbox;
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| 	mode_t omode;
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| {
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| 	register BITCMD *set;
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| 	register mode_t clrval, newmode, value;
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| 
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| 	set = (BITCMD *)bbox;
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| 	newmode = omode;
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| 	for (value = 0;; set++)
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| 		switch(set->cmd) {
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| 		/*
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| 		 * When copying the user, group or other bits around, we "know"
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| 		 * where the bits are in the mode so that we can do shifts to
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| 		 * copy them around.  If we don't use shifts, it gets real
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| 		 * grundgy with lots of single bit checks and bit sets.
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| 		 */
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| 		case 'u':
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| 			value = (newmode & S_IRWXU) >> 6;
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| 			goto common;
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| 
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| 		case 'g':
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| 			value = (newmode & S_IRWXG) >> 3;
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| 			goto common;
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| 
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| 		case 'o':
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| 			value = newmode & S_IRWXO;
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| common:			if (set->cmd2 & CMD2_CLR) {
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| 				clrval =
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| 				    (set->cmd2 & CMD2_SET) ?  S_IRWXO : value;
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| 				if (set->cmd2 & CMD2_UBITS)
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| 					newmode &= ~((clrval<<6) & set->bits);
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| 				if (set->cmd2 & CMD2_GBITS)
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| 					newmode &= ~((clrval<<3) & set->bits);
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| 				if (set->cmd2 & CMD2_OBITS)
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| 					newmode &= ~(clrval & set->bits);
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| 			}
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| 			if (set->cmd2 & CMD2_SET) {
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| 				if (set->cmd2 & CMD2_UBITS)
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| 					newmode |= (value<<6) & set->bits;
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| 				if (set->cmd2 & CMD2_GBITS)
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| 					newmode |= (value<<3) & set->bits;
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| 				if (set->cmd2 & CMD2_OBITS)
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| 					newmode |= value & set->bits;
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| 			}
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| 			break;
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| 
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| 		case '+':
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| 			newmode |= set->bits;
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| 			break;
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| 
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| 		case '-':
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| 			newmode &= ~set->bits;
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| 			break;
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| 
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| 		case 'X':
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| 			if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
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| 				newmode |= set->bits;
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| 			break;
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| 
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| 		case '\0':
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| 		default:
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| #ifdef SETMODE_DEBUG
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| 			(void)printf("getmode:%04o -> %04o\n", omode, newmode);
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| #endif
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| 			return (newmode);
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| 		}
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| }
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| 
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| #define	ADDCMD(a, b, c, d)						\
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| 	if (set >= endset) {						\
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| 		register BITCMD *newset;				\
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| 		setlen += SET_LEN_INCR;					\
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| 		newset = realloc(saveset, sizeof(BITCMD) * setlen);	\
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| 		if (!saveset)						\
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| 			return (NULL);					\
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| 		set = newset + (set - saveset);				\
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| 		saveset = newset;					\
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| 		endset = newset + (setlen - 2);				\
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| 	}								\
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| 	set = addcmd(set, (a), (b), (c), (d))
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| 
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| #define	STANDARD_BITS	(S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
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| 
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| void *
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| setmode(p)
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| 	register char *p;
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| {
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| 	register int perm, who;
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| 	register char op;
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| 	BITCMD *set, *saveset, *endset;
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| 	sigset_t sigset, sigoset;
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| 	mode_t mask;
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| 	int equalopdone, permXbits, setlen;
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| 
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| 	if (!*p)
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| 		return (NULL);
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| 
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| 	/*
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| 	 * Get a copy of the mask for the permissions that are mask relative.
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| 	 * Flip the bits, we want what's not set.  Since it's possible that
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| 	 * the caller is opening files inside a signal handler, protect them
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| 	 * as best we can.
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| 	 */
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| 	sigfillset(&sigset);
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|         (void)sigprocmask(SIG_BLOCK, &sigset, &sigoset);
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| 	(void)umask(mask = umask(0));
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| 	mask = ~mask;
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|         (void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
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| 
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| 	setlen = SET_LEN + 2;
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| 	
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| 	if ((set = malloc((unsigned int)(sizeof(BITCMD) * setlen))) == NULL)
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| 		return (NULL);
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| 	saveset = set;
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| 	endset = set + (setlen - 2);
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| 
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| 	/*
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| 	 * If an absolute number, get it and return; disallow non-octal digits
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| 	 * or illegal bits.
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| 	 */
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| 	if (isdigit(*p)) {
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| 		perm = (mode_t)strtol(p, NULL, 8);
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| 		if (perm & ~(STANDARD_BITS|S_ISTXT)) {
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| 			free(saveset);
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| 			return (NULL);
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| 		}
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| 		while (*++p)
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| 			if (*p < '0' || *p > '7') {
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| 				free(saveset);
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| 				return (NULL);
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| 			}
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| 		ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
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| 		return (saveset);
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| 	}
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| 
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| 	/*
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| 	 * Build list of structures to set/clear/copy bits as described by
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| 	 * each clause of the symbolic mode.
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| 	 */
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| 	for (;;) {
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| 		/* First, find out which bits might be modified. */
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| 		for (who = 0;; ++p) {
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| 			switch (*p) {
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| 			case 'a':
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| 				who |= STANDARD_BITS;
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| 				break;
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| 			case 'u':
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| 				who |= S_ISUID|S_IRWXU;
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| 				break;
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| 			case 'g':
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| 				who |= S_ISGID|S_IRWXG;
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| 				break;
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| 			case 'o':
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| 				who |= S_IRWXO;
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| 				break;
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| 			default:
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| 				goto getop;
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| 			}
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| 		}
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| 
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| getop:		if ((op = *p++) != '+' && op != '-' && op != '=') {
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| 			free(saveset);
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| 			return (NULL);
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| 		}
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| 		if (op == '=')
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| 			equalopdone = 0;
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| 
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| 		who &= ~S_ISTXT;
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| 		for (perm = 0, permXbits = 0;; ++p) {
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| 			switch (*p) {
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| 			case 'r':
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| 				perm |= S_IRUSR|S_IRGRP|S_IROTH;
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| 				break;
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| 			case 's':
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| 				/* If only "other" bits ignore set-id. */
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| 				if (who & ~S_IRWXO)
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| 					perm |= S_ISUID|S_ISGID;
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| 				break;
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| 			case 't':
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| 				/* If only "other" bits ignore sticky. */
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| 				if (who & ~S_IRWXO) {
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| 					who |= S_ISTXT;
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| 					perm |= S_ISTXT;
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| 				}
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| 				break;
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| 			case 'w':
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| 				perm |= S_IWUSR|S_IWGRP|S_IWOTH;
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| 				break;
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| 			case 'X':
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| 				permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
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| 				break;
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| 			case 'x':
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| 				perm |= S_IXUSR|S_IXGRP|S_IXOTH;
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| 				break;
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| 			case 'u':
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| 			case 'g':
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| 			case 'o':
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| 				/*
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| 				 * When ever we hit 'u', 'g', or 'o', we have
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| 				 * to flush out any partial mode that we have,
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| 				 * and then do the copying of the mode bits.
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| 				 */
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| 				if (perm) {
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| 					ADDCMD(op, who, perm, mask);
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| 					perm = 0;
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| 				}
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| 				if (op == '=')
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| 					equalopdone = 1;
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| 				if (op == '+' && permXbits) {
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| 					ADDCMD('X', who, permXbits, mask);
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| 					permXbits = 0;
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| 				}
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| 				ADDCMD(*p, who, op, mask);
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| 				break;
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| 
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| 			default:
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| 				/*
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| 				 * Add any permissions that we haven't already
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| 				 * done.
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| 				 */
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| 				if (perm || (op == '=' && !equalopdone)) {
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| 					if (op == '=')
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| 						equalopdone = 1;
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| 					ADDCMD(op, who, perm, mask);
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| 					perm = 0;
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| 				}
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| 				if (permXbits) {
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| 					ADDCMD('X', who, permXbits, mask);
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| 					permXbits = 0;
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| 				}
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| 				goto apply;
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| 			}
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| 		}
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| 
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| apply:		if (!*p)
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| 			break;
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| 		if (*p != ',')
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| 			goto getop;
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| 		++p;
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| 	}
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| 	set->cmd = 0;
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| #ifdef SETMODE_DEBUG
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| 	(void)printf("Before compress_mode()\n");
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| 	dumpmode(saveset);
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| #endif
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| 	compress_mode(saveset);
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| #ifdef SETMODE_DEBUG
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| 	(void)printf("After compress_mode()\n");
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| 	dumpmode(saveset);
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| #endif
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| 	return (saveset);
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| }
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| 
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| static BITCMD *
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| addcmd(set, op, who, oparg, mask)
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| 	BITCMD *set;
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| 	register int oparg, who;
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| 	register int op;
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| 	unsigned int mask;
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| {
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| 	switch (op) {
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| 	case '=':
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| 		set->cmd = '-';
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| 		set->bits = who ? who : STANDARD_BITS;
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| 		set++;
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| 
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| 		op = '+';
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| 		/* FALLTHROUGH */
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| 	case '+':
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| 	case '-':
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| 	case 'X':
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| 		set->cmd = op;
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| 		set->bits = (who ? who : mask) & oparg;
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| 		break;
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| 
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| 	case 'u':
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| 	case 'g':
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| 	case 'o':
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| 		set->cmd = op;
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| 		if (who) {
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| 			set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
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| 				    ((who & S_IRGRP) ? CMD2_GBITS : 0) |
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| 				    ((who & S_IROTH) ? CMD2_OBITS : 0);
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| 			set->bits = ~0;
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| 		} else {
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| 			set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
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| 			set->bits = mask;
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| 		}
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| 	
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| 		if (oparg == '+')
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| 			set->cmd2 |= CMD2_SET;
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| 		else if (oparg == '-')
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| 			set->cmd2 |= CMD2_CLR;
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| 		else if (oparg == '=')
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| 			set->cmd2 |= CMD2_SET|CMD2_CLR;
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| 		break;
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| 	}
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| 	return (set + 1);
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| }
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| 
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| #ifdef SETMODE_DEBUG
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| static void
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| dumpmode(set)
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| 	register BITCMD *set;
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| {
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| 	for (; set->cmd; ++set)
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| 		(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
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| 		    set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
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| 		    set->cmd2 & CMD2_CLR ? " CLR" : "",
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| 		    set->cmd2 & CMD2_SET ? " SET" : "",
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| 		    set->cmd2 & CMD2_UBITS ? " UBITS" : "",
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| 		    set->cmd2 & CMD2_GBITS ? " GBITS" : "",
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| 		    set->cmd2 & CMD2_OBITS ? " OBITS" : "");
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| }
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| #endif
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| 
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| /*
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|  * Given an array of bitcmd structures, compress by compacting consecutive
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|  * '+', '-' and 'X' commands into at most 3 commands, one of each.  The 'u',
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|  * 'g' and 'o' commands continue to be separate.  They could probably be 
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|  * compacted, but it's not worth the effort.
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|  */
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| static void
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| compress_mode(set)
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| 	register BITCMD *set;
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| {
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| 	register BITCMD *nset;
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| 	register int setbits, clrbits, Xbits, op;
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| 
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| 	for (nset = set;;) {
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| 		/* Copy over any 'u', 'g' and 'o' commands. */
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| 		while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
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| 			*set++ = *nset++;
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| 			if (!op)
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| 				return;
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| 		}
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| 
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| 		for (setbits = clrbits = Xbits = 0;; nset++) {
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| 			if ((op = nset->cmd) == '-') {
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| 				clrbits |= nset->bits;
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| 				setbits &= ~nset->bits;
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| 				Xbits &= ~nset->bits;
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| 			} else if (op == '+') {
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| 				setbits |= nset->bits;
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| 				clrbits &= ~nset->bits;
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| 				Xbits &= ~nset->bits;
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| 			} else if (op == 'X')
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| 				Xbits |= nset->bits & ~setbits;
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| 			else
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| 				break;
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| 		}
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| 		if (clrbits) {
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| 			set->cmd = '-';
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| 			set->cmd2 = 0;
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| 			set->bits = clrbits;
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| 			set++;
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| 		}
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| 		if (setbits) {
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| 			set->cmd = '+';
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| 			set->cmd2 = 0;
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| 			set->bits = setbits;
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| 			set++;
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| 		}
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| 		if (Xbits) {
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| 			set->cmd = 'X';
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| 			set->cmd2 = 0;
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| 			set->bits = Xbits;
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| 			set++;
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| 		}
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| 	}
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| }
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| 
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| /*
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|  * $PchId: setmode.c,v 1.3 2006/05/23 11:57:34 philip Exp $
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|  */
 | 
