/* * Copyright (c) 1987, 1993 *	The Regents of the University of California.  All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in the *    documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software *    must display the following acknowledgement: *	This product includes software developed by the University of *	California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors *    may be used to endorse or promote products derived from this software *    without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <stddef.h>#include <stdlib.h>#include <string.h> char *__findenv(const char *, int *); /* * setenv -- *	Set the value of the environmental variable "name" to be *	"value".  If rewrite is set, replace any current value. */intsetenv(name, value, rewrite)	const char *name;	const char *value;	int rewrite;{	extern char **environ;	static char **alloced;			/* if allocated space before */	char *c;	int l_value, offset; 	if (*value == '=')			/* no `=' in value */		++value;	l_value = strlen(value);	if ((c = __findenv(name, &offset))) {	/* find if already exists */		if (!rewrite)			return (0);		if (strlen(c) >= l_value) {	/* old larger; copy over */			while ( (*c++ = *value++) );			return (0);		}	} else {					/* create new slot */		int cnt;		char **p; 		for (p = environ, cnt = 0; *p; ++p, ++cnt);		if (alloced == environ) {			/* just increase size */			p = (char **)realloc((char *)environ,			    (size_t)(sizeof(char *) * (cnt + 2)));			if (!p)				return (-1);			alloced = environ = p;		}		else {				/* get new space */						/* copy old entries into it */			p = malloc((size_t)(sizeof(char *) * (cnt + 2)));			if (!p)				return (-1);			memcpy(p, environ, cnt * sizeof(char *));			alloced = environ = p;		}		environ[cnt + 1] = NULL;		offset = cnt;	}	for (c = (char *)name; *c && *c != '='; ++c);	/* no `=' in name */	if (!(environ[offset] =			/* name + `=' + value */	    malloc((size_t)((int)(c - name) + l_value + 2))))		return (-1);	for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);	for (*c++ = '='; (*c++ = *value++); );	return (0);} /* * unsetenv(name) -- *	Delete environmental variable "name". */intunsetenv(name)	const char *name;{	extern char **environ;	char **p;	int offset; 	while (__findenv(name, &offset))	/* if set multiple times */		for (p = &environ[offset];; ++p)			if (!(*p = *(p + 1)))				break;	return 0;}