108 lines
3.3 KiB
C
108 lines
3.3 KiB
C
/****************************************************************************
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* sched/environ/env_findvar.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#ifndef CONFIG_DISABLE_ENVIRON
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#include <stdbool.h>
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#include <string.h>
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#include <sched.h>
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#include <assert.h>
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#include "environ/environ.h"
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: env_cmpname
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****************************************************************************/
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static bool env_cmpname(const char *pszname, const char *peqname)
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{
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/* Search until we find anything different in the two names */
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for (; *pszname == *peqname; pszname++, peqname++)
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{
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}
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/* On success, pszname will end with '\0' and peqname with '=' */
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if (*pszname == '\0' && *peqname == '=')
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{
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return true;
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}
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return false;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: env_findvar
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*
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* Description:
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* Search the provided environment structure for the variable of the
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* specified name.
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*
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* Input Parameters:
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* group - The task group containing environment array to be searched.
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* pname - The variable name to find
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*
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* Returned Value:
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* A pointer to the name=value string in the environment
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*
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* Assumptions:
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* - Not called from an interrupt handler
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* - Pre-emption is disabled by caller
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*
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****************************************************************************/
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FAR char *env_findvar(FAR struct task_group_s *group, FAR const char *pname)
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{
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FAR char *ptr;
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FAR char *end;
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/* Verify input parameters */
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DEBUGASSERT(group != NULL && pname != NULL);
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/* Search for a name=value string with matching name */
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end = &group->tg_envp[group->tg_envsize];
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for (ptr = group->tg_envp;
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ptr < end && !env_cmpname(pname, ptr);
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ptr += (strlen(ptr) + 1));
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/* Check for success */
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return (ptr < end) ? ptr : NULL;
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}
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#endif /* CONFIG_DISABLE_ENVIRON */
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