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Diffstat (limited to 'nuttx/sched/env_findvar.c')
-rw-r--r-- | nuttx/sched/env_findvar.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/nuttx/sched/env_findvar.c b/nuttx/sched/env_findvar.c new file mode 100644 index 000000000..a8e94180c --- /dev/null +++ b/nuttx/sched/env_findvar.c @@ -0,0 +1,131 @@ +/**************************************************************************** + * sched/env_findvar.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 <stdbool.h> +#include <string.h> +#include <sched.h> + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: env_cmpname + ****************************************************************************/ + +static bool env_cmpname(const char *pszname, const char *peqname) +{ + /* Search until we find anything different in the two names */ + + for (; *pszname == *peqname; pszname++, peqname++); + + /* On sucess, pszname will end with '\0' and peqname with '=' */ + + if ( *pszname == '\0' && *peqname == '=' ) + { + return true; + } + + return false; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: env_findvar + * + * Description: + * Search the provided environment structure for the variable of the + * specified name. + * + * Parameters: + * envp The environment structre to be searched. + * pname The variable name to find + * + * Return Value: + * A pointer to the name=value string in the environment + * + * Assumptions: + * - Not called from an interrupt handler + * - Pre-emptions is disabled by caller + * + ****************************************************************************/ + +FAR char *env_findvar(environ_t *envp, const char *pname) +{ + char *ret = NULL; + + /* Verify input parameters */ + + if (envp && pname) + { + char *ptr; + char *end = &envp->ev_env[envp->ev_alloc]; + + /* Search for a name=value string with matching name */ + + for (ptr = envp->ev_env; + ptr < end && !env_cmpname( pname, ptr); + ptr += (strlen(ptr) + 1)); + + /* Check for success */ + + if (ptr < end) + { + ret = ptr; + } + } + + return ret; +} + +#endif /* CONFIG_DISABLE_ENVIRON */ + + + |