[apple/libc.git] / stdlib / FreeBSD / getenv.c

/*
 * 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getenv.c	8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdlib/getenv.c,v 1.4 2002/03/21 22:48:41 obrien Exp $");

#include <stdlib.h>
#include <stddef.h>
#include <string.h>

inline char *__findenv(const char *, int *);

/*
 * __findenv --
 *	Returns pointer to value associated with name, if any, else NULL.
 *	Sets offset to be the offset of the name/value combination in the
 *	environmental array, for use by setenv(3) and unsetenv(3).
 *	Explicitly removes '=' in argument name.
 *
 *	This routine *should* be a static; don't use it.
 */
inline char *
__findenv(name, offset)
	const char *name;
	int *offset;
{
	extern char **environ;
	int len, i;
	const char *np;
	char **p, *cp;

	if (name == NULL || environ == NULL)
		return (NULL);
	for (np = name; *np && *np != '='; ++np)
		continue;
	len = np - name;
	for (p = environ; (cp = *p) != NULL; ++p) {
		for (np = name, i = len; i && *cp; i--)
			if (*cp++ != *np++)
				break;
		if (i == 0 && *cp++ == '=') {
			*offset = p - environ;
			return (cp);
		}
	}
	return (NULL);
}

/*
 * getenv --
 *	Returns ptr to value associated with name, if any, else NULL.
 */
char *
getenv(name)
	const char *name;
{
	int offset;

	return (__findenv(name, &offset));
}
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1987, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
9385eb3d A	34	#if defined(LIBC_SCCS) && !defined(lint)
	35	static char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
	36	#endif /* LIBC_SCCS and not lint */
	37	#include <sys/cdefs.h>
	38	__FBSDID("$FreeBSD: src/lib/libc/stdlib/getenv.c,v 1.4 2002/03/21 22:48:41 obrien Exp $");
e9ce8d39 A	39
	40	#include <stdlib.h>
	41	#include <stddef.h>
	42	#include <string.h>
	43
9385eb3d	44	inline char __findenv(const char , int *);
e9ce8d39 A	45
	46	/*
	47	* __findenv --
	48	* Returns pointer to value associated with name, if any, else NULL.
	49	* Sets offset to be the offset of the name/value combination in the
	50	* environmental array, for use by setenv(3) and unsetenv(3).
	51	* Explicitly removes '=' in argument name.
	52	*
	53	* This routine should be a static; don't use it.
	54	*/
9385eb3d	55	inline char *
e9ce8d39	56	__findenv(name, offset)
9385eb3d	57	const char *name;
e9ce8d39 A	58	int *offset;
e9ce8d39 A	59	{
9385eb3d A	60	extern char **environ;
	61	int len, i;
	62	const char *np;
	63	char *p, cp;
e9ce8d39 A	64
	65	if (name == NULL \|\| environ == NULL)
	66	return (NULL);
	67	for (np = name; np && np != '='; ++np)
	68	continue;
	69	len = np - name;
9385eb3d A	70	for (p = environ; (cp = *p) != NULL; ++p) {
	71	for (np = name, i = len; i && *cp; i--)
	72	if (cp++ != np++)
	73	break;
	74	if (i == 0 && *cp++ == '=') {
e9ce8d39	75	*offset = p - environ;
9385eb3d	76	return (cp);
e9ce8d39	77	}
9385eb3d	78	}
e9ce8d39 A	79	return (NULL);
e9ce8d39 A	80	}
9385eb3d A	81
	82	/*
	83	* getenv --
	84	* Returns ptr to value associated with name, if any, else NULL.
	85	*/
	86	char *
	87	getenv(name)
	88	const char *name;
	89	{
	90	int offset;
	91
	92	return (__findenv(name, &offset));
	93	}