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Diffstat (limited to 'nuttx/sched/environ/env_getenv.c')
-rw-r--r-- | nuttx/sched/environ/env_getenv.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/nuttx/sched/environ/env_getenv.c b/nuttx/sched/environ/env_getenv.c new file mode 100644 index 000000000..6a030e3f6 --- /dev/null +++ b/nuttx/sched/environ/env_getenv.c @@ -0,0 +1,133 @@ +/**************************************************************************** + * env_getenv.c + * + * Copyright (C) 2007, 2008, 2013 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 <stdlib.h> +#include <errno.h> + +#include "os_internal.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 */ + |