106 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*	$OpenBSD: setenv.c,v 1.9 2005/08/08 08:05:37 espie Exp $ */
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| /*
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|  * Copyright (c) 1987 Regents of the University of California.
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|  * All rights reserved.
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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. 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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| #include <stdlib.h>
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| #include <string.h>
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| 
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| char *__findenv(const char *name, int *offset);
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| 
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| extern char **environ;
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| 
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| /*
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|  * setenv --
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|  *	Set the value of the environmental variable "name" to be
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|  *	"value".  If rewrite is set, replace any current value.
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|  */
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| int
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| setenv(const char *name, const char *value, int rewrite)
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| {
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| 	static char **lastenv;			/* last value of environ */
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| 	char *C;
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| 	int l_value, offset;
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| 
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| 	if (*value == '=')			/* no `=' in value */
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| 		++value;
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| 	l_value = strlen(value);
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| 	if ((C = __findenv(name, &offset))) {	/* find if already exists */
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| 		if (!rewrite)
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| 			return (0);
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| 		if ((int)strlen(C) >= l_value) {	/* old larger; copy over */
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| 			while ((*C++ = *value++))
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| 				;
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| 			return (0);
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| 		}
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| 	} else {					/* create new slot */
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| 		size_t cnt;
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| 		char **P;
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| 
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| 		for (P = environ; *P != NULL; P++)
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| 			;
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| 		cnt = P - environ;
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|         P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
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| 		if (!P)
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| 			return (-1);
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| 		if (lastenv != environ)
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| 			memcpy(P, environ, cnt * sizeof(char *));
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| 		lastenv = environ = P;
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| 		offset = cnt;
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| 		environ[cnt + 1] = NULL;
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| 	}
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| 	for (C = (char *)name; *C && *C != '='; ++C)
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| 		;				/* no `=' in name */
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| 	if (!(environ[offset] =			/* name + `=' + value */
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| 	    malloc((size_t)((int)(C - name) + l_value + 2))))
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| 		return (-1);
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| 	for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
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| 		;
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| 	for (*C++ = '='; (*C++ = *value++); )
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| 		;
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| 	return (0);
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| }
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| 
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| /*
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|  * unsetenv(name) --
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|  *	Delete environmental variable "name".
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|  */
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| int
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| unsetenv(const char *name)
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| {
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| 	char **P;
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| 	int offset;
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| 
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| 	while (__findenv(name, &offset))	/* if set multiple times */
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| 		for (P = &environ[offset];; ++P)
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| 			if (!(*P = *(P + 1)))
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| 				break;
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| 
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|         return 0;
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| }
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