auto import from //depot/cupcake/@135843

libc/stdlib/getenv.c

@@ -0,0 +1,80 @@
+/*	$OpenBSD: getenv.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */
+/*
+ * 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. 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 <stdlib.h>
+#include <string.h>
+
+char *__findenv(const char *name, int *offset);
+
+/*
+ * __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.
+ */
+char *
+__findenv(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)
+		;
+	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(const char *name)
+{
+	int offset;
+
+	return (__findenv(name, &offset));
+}