/**************************************************************************** * env_getenv.c * * Copyright (C) 2007, 2008, 2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #ifndef CONFIG_DISABLE_ENVIRON #include #include #include #include #include "sched/sched.h" #include "environ/environ.h" /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: getenv * * Description: * The getenv() function searches the environment list for a string that * matches the string pointed to by name. * * Parameters: * name - The name of the variable to find. * * Return Value: * The value of the valiable (read-only) or NULL on failure * * Assumptions: * Not called from an interrupt handler * ****************************************************************************/ FAR char *getenv(const char *name) { FAR struct tcb_s *rtcb; FAR struct task_group_s *group; FAR char *pvar; FAR char *pvalue = NULL; int ret = OK; /* Verify that a string was passed */ if (!name) { ret = EINVAL; goto errout; } /* Get a reference to the thread-private environ in the TCB. */ sched_lock(); rtcb = (FAR struct tcb_s*)g_readytorun.head; group = rtcb->group; /* Check if the variable exists */ if ( !group || (pvar = env_findvar(group, name)) == NULL) { ret = ENOENT; goto errout_with_lock; } /* It does! Get the value sub-string from the name=value string */ pvalue = strchr(pvar, '='); if (!pvalue) { /* 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 */