/****************************************************************************
 * include/nuttx/environ.h
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

#ifndef __INCLUDE_NUTTX_ENVIRON_H
#define __INCLUDE_NUTTX_ENVIRON_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#ifndef CONFIG_DISABLE_ENVIRON

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Public Types
 ****************************************************************************/

/* Callback function used with env_foreach() */

typedef CODE int (*env_foreach_t)(FAR void *arg, FAR const char *pair);

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif

/****************************************************************************
 * Name: env_foreach
 *
 * Description:
 *   Search the provided environment structure for the variable of the
 *   specified name.
 *
 *   This is an internal OS function and should not be used by applications.
 *
 * Input Parameters:
 *   group - The task group containing environment array to be searched.
 *   cb    - The callback function to be invoked for each environment
 *           variable.
 *
 * Returned Value:
 *   Zero if the all environment variables have been traversed.  A non-zero
 *   value means that the callback function requested early termination by
 *   returning a nonzero value.
 *
 * Assumptions:
 *   - Not called from an interrupt handler
 *   - Pre-emption is disabled by caller
 *
 ****************************************************************************/

struct task_group_s;  /* Forward reference */
int env_foreach(FAR struct task_group_s *group, env_foreach_t cb,
                FAR void *arg);

#undef EXTERN
#ifdef __cplusplus
}
#endif

#endif /* !CONFIG_DISABLE_ENVIRON */
#endif /* __INCLUDE_NUTTX_ENVIRON_H */
