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/****************************************************************************
* sched/env_removevar.c
*
* Copyright (C) 2007, 2009 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 <string.h>
#include <sched.h>
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: env_removevar
*
* Description:
* Remove the referenced name=value pair from the environment
*
* Parameters:
* envp The environment containing the name=value pair
* pvar A pointer to the name=value pair in the restroom
*
* Return Value:
* Zero on success
*
* Assumptions:
* - Not called from an interrupt handler
* - Caller has pre-emptions disabled
* - Caller will reallocate the environment structure to the correct size
*
****************************************************************************/
int env_removevar(environ_t *envp, char *pvar)
{
int ret = ERROR;
if (envp && pvar)
{
/* Verify that the pointer lies within the environment region */
int alloc = envp->ev_alloc; /* Size of the allocated environment */
char *end = &envp->ev_env[alloc]; /* Pointer to the end+1 of the environment */
if (pvar >= envp->ev_env && pvar < end)
{
/* Set up for the removal */
int len = strlen(pvar) + 1; /* Length of name=value string to remove */
char *src = &pvar[len]; /* Address of name=value string after */
char *dest = pvar; /* Location to move the next string */
int count = end - src; /* Number of bytes to move (might be zero) */
/* Move all of the environment strings after the removed one 'down.'
* this is inefficient, but robably not high duty.
*/
while (count-- > 0)
{
*dest++ = *src++;
}
/* Then set to the new allocation size. The caller is expected to
* call realloc at some point but we don't do that here because the
* caller may add more stuff to the environment.
*/
envp->ev_alloc -= len;
ret = OK;
}
}
return ret;
}
#endif /* CONFIG_DISABLE_ENVIRON */
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