incubator-nuttx/sched/environ/env_unsetenv.c

93 lines
2.6 KiB
C

/****************************************************************************
* sched/environ/env_unsetenv.c
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#ifndef CONFIG_DISABLE_ENVIRON
#include <sched.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include "sched/sched.h"
#include "environ/environ.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: unsetenv
*
* Description:
* The unsetenv() function deletes the variable name from the environment.
*
* Input Parameters:
* name - The name of the variable to delete
*
* Returned Value:
* Zero on success
*
* Assumptions:
* Not called from an interrupt handler
*
****************************************************************************/
int unsetenv(FAR const char *name)
{
FAR struct tcb_s *rtcb = this_task();
FAR struct task_group_s *group = rtcb->group;
ssize_t idx;
DEBUGASSERT(group);
/* Check the incoming parameter */
if (name == NULL || *name == '\0' || strchr(name, '=') != NULL)
{
set_errno(EINVAL);
return ERROR;
}
/* Check if the variable exists */
sched_lock();
if (group && (idx = env_findvar(group, name)) >= 0)
{
/* It does! Remove the name=value pair from the environment. */
env_removevar(group, idx);
}
sched_unlock();
return OK;
}
#endif /* CONFIG_DISABLE_ENVIRON */