nuttx/sched/environ/env_foreach.c

112 lines
3.7 KiB
C

/****************************************************************************
* sched/environ/env_foreach.c
*
* Copyright (C) 2018 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 <stdbool.h>
#include <string.h>
#include <sched.h>
#include <nuttx/environ.h>
#include "environ/environ.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: env_foreach
*
* Description:
* Search the provided environment structure for the variable of the
* specified name.
*
* 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-emptions is disabled by caller
*
****************************************************************************/
int env_foreach(FAR struct task_group_s *group, env_foreach_t cb, FAR void *arg)
{
FAR char *ptr;
FAR char *end;
int ret = OK;
/* Verify input parameters */
DEBUGASSERT(group != NULL && cb != NULL);
/* Search for a name=value string with matching name */
end = &group->tg_envp[group->tg_envsize];
for (ptr = group->tg_envp; ptr < end; ptr += (strlen(ptr) + 1))
{
/* Perform the callback */
ret = cb(arg, ptr);
/* Terminate the traversal early if the callback so requests by
* returning a non-zero value.
*/
if (ret != 0)
{
break;
}
}
return ret;
}
#endif /* CONFIG_DISABLE_ENVIRON */