Add private __getenv_reentrant()

A reentrant variant of getenv().

headers/private/libroot/stdlib_private.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2013, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _LIBROOT_STDLIB_PRIVATE_H
+#define _LIBROOT_STDLIB_PRIVATE_H
+
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+
+__BEGIN_DECLS
+
+
+ssize_t	__getenv_reentrant(const char* name, char* buffer,
+			size_t bufferSize);
+
+
+__END_DECLS
+
+
+#endif	/* _LIBROOT_STDLIB_PRIVATE_H */

src/system/libroot/posix/stdlib/env.cpp

@@ -15,6 +15,7 @@
 #include <libroot_private.h>
 #include <locks.h>
 #include <runtime_loader.h>
+#include <stdlib_private.h>
 #include <syscall_utils.h>
 #include <user_runtime.h>
 
@@ -315,3 +316,21 @@ putenv(const char *string)
 	RETURN_AND_SET_ERRNO(status);
 }
 
+
+ssize_t
+__getenv_reentrant(const char* name, char* buffer, size_t bufferSize)
+{
+	size_t nameLength = strlen(name);
+
+	lock_variables();
+
+	char* value = find_variable(name, nameLength, NULL);
+	ssize_t result = value != NULL
+		? strlcpy(buffer, value + nameLength + 1, bufferSize)
+		: B_NAME_NOT_FOUND;
+
+	unlock_variables();
+
+	return result;
+}
+