425 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			425 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*-
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|  * Copyright (c) 1990 The Regents of the University of California.
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|  * 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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|  * John B. Roll Jr.
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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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| #ifndef lint
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| char copyright[] =
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| "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
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|  All rights reserved.\n";
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| #endif /* not lint */
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| 
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| #ifndef lint
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| static char sccsid[] = "@(#)xargs.c	5.11 (Berkeley) 6/19/91";
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| #endif /* not lint */
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| 
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| #include <sys/types.h>
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| #include <sys/wait.h>
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| #include <errno.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <unistd.h>
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| #include <limits.h>
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| #include <fcntl.h>
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| #include <stdarg.h>
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| #if __minix
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| #define _PATH_ECHO	"/bin/echo"
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| #else
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| #include "pathnames.h"
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| #endif
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| 
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| #ifndef ARG_MAX
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| #define ARG_MAX		(sizeof(int) == 2 ? 4096 : 128 * 1024)
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| #endif
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| 
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| int exit_status = 0;
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| int tflag;
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| void err(const char *, ...);
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| void run(char **argv);
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| void usage(void);
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| 
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| int main(int argc, char **argv)
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| {
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| 	extern int optind;
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| 	extern char *optarg;
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| 	register int ch;
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| 	register char *p, *bbp, *ebp, **bxp, **exp, **xp;
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| 	int cnt, indouble, insingle, nargs, nflag, nline, xflag, zflag;
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| 	char **av, *argp;
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| 
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| 	/*
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| 	 * POSIX.2 limits the exec line length to ARG_MAX - 2K.  Running that
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| 	 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K.  Given
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| 	 * that the smallest argument is 2 bytes in length, this means that
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| 	 * the number of arguments is limited to:
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| 	 *
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| 	 *	 (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2.
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| 	 *
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| 	 * We arbitrarily limit the number of arguments to 5000.  This is
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| 	 * allowed by POSIX.2 as long as the resulting minimum exec line is
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| 	 * at least LINE_MAX.  Realloc'ing as necessary is possible, but
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| 	 * probably not worthwhile.
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| 	 */
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| #if !__minix || __minix_vmd
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| 	nargs = 5000;
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| 	nline = ARG_MAX - 4 * 1024;
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| #else
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| 	/* Things are more cramped under standard Minix. */
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| 	nargs = 80 * sizeof(int);
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| 	nline = ARG_MAX - 512 * sizeof(int);
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| #endif
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| 	nflag = xflag = zflag = 0;
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| 	while ((ch = getopt(argc, argv, "n:s:tx0")) != EOF)
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| 		switch(ch) {
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| 		case 'n':
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| 			nflag = 1;
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| 			if ((nargs = atoi(optarg)) <= 0)
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| 				err("illegal argument count");
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| 			break;
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| 		case 's':
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| 			nline = atoi(optarg);
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| 			break;
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| 		case 't':
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| 			tflag = 1;
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| 			break;
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| 		case 'x':
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| 			xflag = 1;
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| 			break;
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| 		case '0':
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| 			zflag = 1;
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| 			break;
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| 		case '?':
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| 		default:
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| 			usage();
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| 	}
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| 	argc -= optind;
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| 	argv += optind;
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| 
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| 	if (xflag && !nflag)
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| 		usage();
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| 
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| 	/*
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| 	 * Allocate pointers for the utility name, the utility arguments,
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| 	 * the maximum arguments to be read from stdin and the trailing
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| 	 * NULL.
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| 	 */
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| 	if (!(av = bxp =
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| 	    malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **))))
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| 		err("%s", strerror(errno));
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| 
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| 	/*
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| 	 * Use the user's name for the utility as argv[0], just like the
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| 	 * shell.  Echo is the default.  Set up pointers for the user's
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| 	 * arguments.
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| 	 */
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| 	if (!*argv)
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| 		cnt = strlen(*bxp++ = _PATH_ECHO);
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| 	else {
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| 		cnt = 0;
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| 		do {
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| 			cnt += strlen(*bxp++ = *argv) + 1;
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| 		} while (*++argv);
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| 	}
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| 
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| 	/*
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| 	 * Set up begin/end/traversing pointers into the array.  The -n
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| 	 * count doesn't include the trailing NULL pointer, so the malloc
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| 	 * added in an extra slot.
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| 	 */
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| 	exp = (xp = bxp) + nargs;
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| 
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| 	/*
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| 	 * Allocate buffer space for the arguments read from stdin and the
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| 	 * trailing NULL.  Buffer space is defined as the default or specified
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| 	 * space, minus the length of the utility name and arguments.  Set up
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| 	 * begin/end/traversing pointers into the array.  The -s count does
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| 	 * include the trailing NULL, so the malloc didn't add in an extra
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| 	 * slot.
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| 	 */
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| 	nline -= cnt;
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| 	if (nline <= 0)
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| 		err("insufficient space for command");
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| 
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| 	if (!(bbp = malloc((u_int)nline + 1)))
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| 		err("%s", strerror(errno));
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| 	ebp = (argp = p = bbp) + nline - 1;
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| 
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| 	if (zflag) {
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| 		/* Read pathnames terminated by null bytes as produced by
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| 		 * find ... -print0.  No comments in this code, see further
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| 		 * below.
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| 		 */
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| 		for (;;)
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| 			switch(ch = getchar()) {
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| 			case EOF:
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| 				if (p == bbp)
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| 					exit(exit_status);
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| 
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| 				if (argp == p) {
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| 					*xp = NULL;
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| 					run(av);
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| 					exit(exit_status);
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| 				}
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| 				/*FALL THROUGH*/
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| 			case '\0':
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| 				if (argp == p)
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| 					continue;
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| 
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| 				*p = '\0';
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| 				*xp++ = argp;
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| 
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| 				if (xp == exp || p == ebp || ch == EOF) {
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| 					if (xflag && xp != exp && p == ebp)
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| 						err(
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| 					   "insufficient space for arguments");
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| 					*xp = NULL;
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| 					run(av);
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| 					if (ch == EOF)
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| 						exit(exit_status);
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| 					p = bbp;
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| 					xp = bxp;
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| 				} else
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| 					++p;
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| 				argp = p;
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| 				break;
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| 			default:
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| 				if (p < ebp) {
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| 					*p++ = ch;
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| 					break;
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| 				}
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| 
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| 				if (bxp == xp)
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| 					err("insufficient space for argument");
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| 				if (xflag)
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| 					err("insufficient space for arguments");
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| 
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| 				*xp = NULL;
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| 				run(av);
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| 				xp = bxp;
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| 				cnt = ebp - argp;
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| 				bcopy(argp, bbp, cnt);
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| 				p = (argp = bbp) + cnt;
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| 				*p++ = ch;
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| 				break;
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| 			}
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| 		/* NOTREACHED */
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| 	}
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| 
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| 	for (insingle = indouble = 0;;)
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| 		switch(ch = getchar()) {
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| 		case EOF:
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| 			/* No arguments since last exec. */
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| 			if (p == bbp)
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| 				exit(exit_status);
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| 
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| 			/* Nothing since end of last argument. */
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| 			if (argp == p) {
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| 				*xp = NULL;
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| 				run(av);
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| 				exit(exit_status);
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| 			}
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| 			goto arg1;
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| 		case ' ':
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| 		case '\t':
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| 			/* Quotes escape tabs and spaces. */
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| 			if (insingle || indouble)
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| 				goto addch;
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| 			goto arg2;
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| 		case '\n':
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| 			/* Empty lines are skipped. */
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| 			if (argp == p)
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| 				continue;
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| 
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| 			/* Quotes do not escape newlines. */
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| arg1:			if (insingle || indouble)
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| 				 err("unterminated quote");
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| 
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| arg2:			*p = '\0';
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| 			*xp++ = argp;
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| 
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| 			/*
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| 			 * If max'd out on args or buffer, or reached EOF,
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| 			 * run the command.  If xflag and max'd out on buffer
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| 			 * but not on args, object.
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| 			 */
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| 			if (xp == exp || p == ebp || ch == EOF) {
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| 				if (xflag && xp != exp && p == ebp)
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| 					err("insufficient space for arguments");
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| 				*xp = NULL;
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| 				run(av);
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| 				if (ch == EOF)
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| 					exit(exit_status);
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| 				p = bbp;
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| 				xp = bxp;
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| 			} else
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| 				++p;
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| 			argp = p;
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| 			break;
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| 		case '\'':
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| 			if (indouble)
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| 				goto addch;
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| 			insingle = !insingle;
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| 			break;
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| 		case '"':
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| 			if (insingle)
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| 				goto addch;
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| 			indouble = !indouble;
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| 			break;
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| 		case '\\':
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| 			/* Backslash escapes anything, is escaped by quotes. */
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| 			if (!insingle && !indouble && (ch = getchar()) == EOF)
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| 				err("backslash at EOF");
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| 			/* FALLTHROUGH */
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| 		default:
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| addch:			if (p < ebp) {
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| 				*p++ = ch;
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| 				break;
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| 			}
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| 
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| 			/* If only one argument, not enough buffer space. */
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| 			if (bxp == xp)
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| 				err("insufficient space for argument");
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| 			/* Didn't hit argument limit, so if xflag object. */
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| 			if (xflag)
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| 				err("insufficient space for arguments");
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| 
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| 			*xp = NULL;
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| 			run(av);
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| 			xp = bxp;
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| 			cnt = ebp - argp;
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| 			bcopy(argp, bbp, cnt);
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| 			p = (argp = bbp) + cnt;
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| 			*p++ = ch;
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| 			break;
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| 		}
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| 	/* NOTREACHED */
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| }
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| 
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| void run(char **argv)
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| {
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| 	register char **p;
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| 	pid_t pid;
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| 	int noinvoke;
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| 	int status;
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| 	int pfd[2];
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| 
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| 	if (tflag) {
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| 		(void)fprintf(stderr, "%s", *argv);
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| 		for (p = argv + 1; *p; ++p)
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| 			(void)fprintf(stderr, " %s", *p);
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| 		(void)fprintf(stderr, "\n");
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| 		(void)fflush(stderr);
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| 	}
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| 	if (pipe(pfd) < 0) err("pipe: %s", strerror(errno));
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| 
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| 	switch(pid = fork()) {
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| 	case -1:
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| 		err("fork: %s", strerror(errno));
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| 	case 0:
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| 		close(pfd[0]);
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| 		fcntl(pfd[1], F_SETFD, fcntl(pfd[1], F_GETFD) | FD_CLOEXEC);
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| 
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| 		execvp(argv[0], argv);
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| 		noinvoke = (errno == ENOENT) ? 127 : 126;
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| 		(void)fprintf(stderr,
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| 		    "xargs: %s exec failed: %s.\n", argv[0], strerror(errno));
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| 
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| 		/* Modern way of returning noinvoke instead of a dirty vfork()
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| 		 * trick:					(kjb)
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| 		 */
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| 		write(pfd[1], &noinvoke, sizeof(noinvoke));
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| 		_exit(-1);
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| 	}
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| 	close(pfd[1]);
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| 	if (read(pfd[0], &noinvoke, sizeof(noinvoke)) < sizeof(noinvoke))
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| 		noinvoke = 0;
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| 	close(pfd[0]);
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| 
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| 	pid = waitpid(pid, &status, 0);
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| 	if (pid == -1)
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| 		err("waitpid: %s", strerror(errno));
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| 
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| 	/*
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| 	 * If we couldn't invoke the utility or the utility didn't exit
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| 	 * properly, quit with 127 or 126 respectively.
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| 	 */
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| 	if (noinvoke)
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| 		exit(noinvoke);
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| 
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| 	/*
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| 	 * According to POSIX, we have to exit if the utility exits with
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| 	 * a 255 status, or is interrupted by a signal.   xargs is allowed
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| 	 * to return any exit status between 1 and 125 in these cases, but
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| 	 * we'll use 124 and 125, the same values used by GNU xargs.
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| 	 */
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| 	if (WIFEXITED(status)) {
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| 		if (WEXITSTATUS (status) == 255) {
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| 			fprintf (stderr, "xargs: %s exited with status 255\n",
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| 				 argv[0]);
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| 			exit(124);
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| 		} else if (WEXITSTATUS (status) != 0) {
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| 			exit_status = 123;
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| 		}
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| 	} else if (WIFSTOPPED (status)) {
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| 		fprintf (stderr, "xargs: %s terminated by signal %d\n",
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| 			 argv[0], WSTOPSIG (status));
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| 		exit(125);
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| 	} else if (WIFSIGNALED (status)) {
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| 		fprintf (stderr, "xargs: %s terminated by signal %d\n",
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| 			 argv[0], WTERMSIG (status));
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| 		exit(125);
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| 	}
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| }
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| 
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| void usage(void)
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| {
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| 	(void)fprintf(stderr,
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| "usage: xargs [-t0] [[-x] -n number] [-s size] [utility [argument ...]]\n");
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| 	exit(1);
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| }
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| 
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| void err(const char *fmt, ...)
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| {
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| 	va_list ap;
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| 
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| 	va_start(ap, fmt);
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| 	(void)fprintf(stderr, "xargs: ");
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| 	(void)vfprintf(stderr, fmt, ap);
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| 	va_end(ap);
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| 	(void)fprintf(stderr, "\n");
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| 	exit(1);
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| 	/* NOTREACHED */
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| }
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