diff options
Diffstat (limited to 'nuttx/sched/env_unsetenv.c')
-rw-r--r-- | nuttx/sched/env_unsetenv.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/nuttx/sched/env_unsetenv.c b/nuttx/sched/env_unsetenv.c new file mode 100644 index 000000000..52469fac9 --- /dev/null +++ b/nuttx/sched/env_unsetenv.c @@ -0,0 +1,138 @@ +/**************************************************************************** + * sched/env_unsetenv.c + * + * Copyright (C) 2007, 2009, 2011 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 <sched.h> +#include <string.h> +#include <errno.h> + +#include <nuttx/kmalloc.h> + +#include "os_internal.h" +#include "env_internal.h" + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: unsetenv + * + * Description: + * The unsetenv() function deletes the variable name from the environment. + * + * Parameters: + * name - The name of the variable to delete + * + * Return Value: + * Zero on success + * + * Assumptions: + * Not called from an interrupt handler + * + ****************************************************************************/ + +int unsetenv(const char *name) +{ + FAR _TCB *rtcb; + FAR environ_t *envp; + FAR char *pvar; + int ret = OK; + + /* Verify input parameter */ + + if (!name) + { + ret = EINVAL; + goto errout; + } + + /* Get a reference to the thread-private environ in the TCB.*/ + + sched_lock(); + rtcb = (FAR _TCB*)g_readytorun.head; + envp = rtcb->envp; + + /* Check if the variable exists */ + + if ( envp && (pvar = env_findvar(envp, name)) != NULL) + { + int alloc; + environ_t *tmp; + + /* It does! Remove the name=value pair from the environment. */ + + (void)env_removevar(envp, pvar); + + /* Reallocate the new environment buffer */ + + alloc = envp->ev_alloc; + tmp = (environ_t*)krealloc(envp, SIZEOF_ENVIRON_T(alloc)); + if (!tmp) + { + ret = ENOMEM; + goto errout_with_lock; + } + + /* Save the new environment pointer (it might have changed due to reallocation. */ + + rtcb->envp = tmp; + } + + sched_unlock(); + return OK; + +errout_with_lock: + sched_unlock(); +errout: + errno = ret; + return ERROR; +} + +#endif /* CONFIG_DISABLE_ENVIRON */ + + + |