replacement putenv()

[Ben Lindstrom]

Can we get this as a replacement to the current putenv()?  It's out of the
OpenBSD source tree and is a complete replacement instead of a wrapper
around setenv().

Thanks.

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#ifndef  HAVE_SETENV
/* 
 **  Borrowed from OpenBSD 2.6.  Some platforms don't even support putenv()
 **  So therefor we need a real setenv(). 
 */
int
setenv(name, value, rewrite)
	register const char *name;
	register const char *value;
	int rewrite;
{
	extern char **environ;
	static int alloced;			/* if allocated space before */
	register char *C;
	int l_value, offset;
	char *__findenv();

	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 */
		register int	cnt;
		register char	**P;

		for (P = environ, cnt = 0; *P; ++P, ++cnt);
		if (alloced) {			/* just increase size */
			P = (char **)realloc((void *)environ,
			    (size_t)(sizeof(char *) * (cnt + 2)));
			if (!P)
				return (-1);
			environ = P;
		}
		else {				/* get new space */
			alloced = 1;		/* copy old entries into it */
			P = (char **)malloc((size_t)(sizeof(char *) *
			    (cnt + 2)));
			if (!P)
				return (-1);
			bcopy(environ, P, cnt * sizeof(char *));
			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);
}

char *
__findenv(name, offset)
	register const char *name;
	int *offset;
{
	extern char **environ;
	register int len, i;
	register const char *np;
	register char **p, *cp;

	if (name == NULL || environ == NULL)
		return (NULL);
	for (np = name; *np && *np != '='; ++np)
		;
	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);
}
#endif /* !HAVE_SETENV */