d77b53957c
this commit optimize the env api speed Signed-off-by: wangbowen6 <wangbowen6@xiaomi.com>
112 lines
3.0 KiB
C
112 lines
3.0 KiB
C
/****************************************************************************
|
|
* sched/environ/env_getenv.c
|
|
*
|
|
* 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 <stdlib.h>
|
|
#include <errno.h>
|
|
|
|
#include "sched/sched.h"
|
|
#include "environ/environ.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: getenv
|
|
*
|
|
* Description:
|
|
* The getenv() function searches the environment list for a string that
|
|
* matches the string pointed to by name.
|
|
*
|
|
* Input Parameters:
|
|
* name - The name of the variable to find.
|
|
*
|
|
* Returned Value:
|
|
* The value of the valiable (read-only) or NULL on failure
|
|
*
|
|
* Assumptions:
|
|
* Not called from an interrupt handler
|
|
*
|
|
****************************************************************************/
|
|
|
|
FAR char *getenv(FAR const char *name)
|
|
{
|
|
FAR struct tcb_s *rtcb;
|
|
FAR struct task_group_s *group;
|
|
FAR char *pvalue = NULL;
|
|
ssize_t ret = OK;
|
|
|
|
/* Verify that a string was passed */
|
|
|
|
if (name == NULL)
|
|
{
|
|
ret = -EINVAL;
|
|
goto errout;
|
|
}
|
|
|
|
/* Get a reference to the thread-private environ in the TCB. */
|
|
|
|
sched_lock();
|
|
rtcb = this_task();
|
|
group = rtcb->group;
|
|
|
|
/* Check if the variable exists */
|
|
|
|
if (group == NULL || (ret = env_findvar(group, name)) < 0)
|
|
{
|
|
goto errout_with_lock;
|
|
}
|
|
|
|
/* It does! Get the value sub-string from the name=value string */
|
|
|
|
pvalue = strchr(group->tg_envp[ret], '=');
|
|
if (pvalue == NULL)
|
|
{
|
|
/* The name=value string has no '=' This is a bug! */
|
|
|
|
ret = -EINVAL;
|
|
goto errout_with_lock;
|
|
}
|
|
|
|
/* Adjust the pointer so that it points to the value right after the '=' */
|
|
|
|
pvalue++;
|
|
sched_unlock();
|
|
return pvalue;
|
|
|
|
errout_with_lock:
|
|
sched_unlock();
|
|
errout:
|
|
set_errno(-ret);
|
|
return NULL;
|
|
}
|
|
|
|
#endif /* CONFIG_DISABLE_ENVIRON */
|