From 170ab11075d3be56e89d6444abf1148329130f4b Mon Sep 17 00:00:00 2001 From: Joe Hershberger Date: Tue, 11 Dec 2012 22:16:24 -0600 Subject: env: Add support for callbacks to environment vars Add support for per-variable callbacks to the "hashtable" functions. Signed-off-by: Joe Hershberger !!!fix comment in callback --- include/env_attr.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 include/env_attr.h (limited to 'include/env_attr.h') diff --git a/include/env_attr.h b/include/env_attr.h new file mode 100644 index 0000000000..6ef114f5da --- /dev/null +++ b/include/env_attr.h @@ -0,0 +1,55 @@ +/* + * (C) Copyright 2012 + * Joe Hershberger, National Instruments, joe.hershberger@ni.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#ifndef __ENV_ATTR_H__ +#define __ENV_ATTR_H__ + +#define ENV_ATTR_LIST_DELIM ',' +#define ENV_ATTR_SEP ':' + +/* + * env_attr_walk takes as input an "attr_list" that takes the form: + * attributes = [^,:\s]* + * entry = name[:attributes] + * list = entry[,list] + * It will call the "callback" function with the "name" and attribute as "value" + * The callback may return a non-0 to abort the list walk. + * This return value will be passed through to the caller. + * 0 is returned on success. + */ +extern int env_attr_walk(const char *attr_list, + int (*callback)(const char *name, const char *value)); + +/* + * env_attr_lookup takes as input an "attr_list" with the same form as above. + * It also takes as input a "name" to look for. + * If the name is found in the list, it's value is copied into "attributes". + * There is no protection on attributes being too small for the value. + * It returns -1 if attributes is NULL, 1 if "name" is not found, 2 if + * "attr_list" is NULL. + * Returns 0 on success. + */ +extern int env_attr_lookup(const char *attr_list, const char *name, + char *attributes); + +#endif /* __ENV_ATTR_H__ */ -- cgit v1.2.1