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diff --git a/nuttx/sched/env_share.c b/nuttx/sched/env_share.c
new file mode 100644
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+/****************************************************************************
+ * sched/env_share.c
+ *
+ *   Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 NuttX 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 COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifndef CONFIG_DISABLE_ENVIRON
+
+#include <sched.h>
+#include <errno.h>
+
+#include "os_internal.h"
+#include "env_internal.h"
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: env_share
+ *
+ * Description:
+ *   Increment the reference count on the internal environment structure of
+ *   a task.  This is the action that is performed when a new pthread is
+ *   created: The new pthread shares the environment with its parent.
+ *
+ * Parameters:
+ *   ptcb The new TCB to receive the shared environment.
+ *
+ * Return Value:
+ *   A pointer to a specified TCB's environment structure with an incremented
+ *   reference count.
+ *
+ * Assumptions:
+ *   Not called from an interrupt handler.
+ *
+ ****************************************************************************/
+
+int env_share(FAR _TCB *ptcb)
+{
+  int ret = OK;
+  if (!ptcb)
+    {
+      ret = -EINVAL;
+    }
+  else
+    {
+      FAR _TCB *parent = (FAR _TCB*)g_readytorun.head;
+      environ_t *envp = parent->envp;
+
+      /* Pre-emption must be disabled throughout the following because the
+       * environment is shared.
+       */
+
+      sched_lock();
+
+      /* Does the parent task have an environment? */
+
+      if (envp)
+        {
+          /* Yes.. increment the reference count on the environment */
+
+          envp->ev_crefs++;
+        }
+
+      /* Then share the environment */
+
+      ptcb->envp = envp;
+      sched_unlock();
+    }
+
+  return ret;
+}
+
+#endif /* CONFIG_DISABLE_ENVIRON */
+
+
+