major re-work of dialplan functions, including:

- locking of functions list during registration/unregistration/searching
 - rename of function description structure to be consistent with the rest of the API
 - addition of 'desc' element to description structure, for detailed description (like applications)
 - addition of 'show function' CLI command to show function details
 - conversion of existing functions to use uppercase names to match policy
 - creation of new 'pbx_functions.so' module to contain standard 'builtin' functions
 - removal of all builtin functions from pbx.c and apps and placement into new 'funcs' directory


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5583 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_env.c

@@ -0,0 +1,56 @@
+/*
+ * Asterisk -- A telephony toolkit for Linux.
+ *
+ * MD5 digest related dialplan functions
+ * 
+ * Copyright (C) 2005, Digium, Inc.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/logger.h"
+#include "asterisk/utils.h"
+#include "asterisk/app.h"
+
+static char *builtin_function_env_read(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len) 
+{
+	char *ret = "";
+
+	if (data) {
+		ret = getenv(data);
+		if (!ret)
+			ret = "";
+	}
+	ast_copy_string(buf, ret, len);
+
+	return buf;
+}
+
+static void builtin_function_env_write(struct ast_channel *chan, char *cmd, char *data, const char *value) 
+{
+	if (data && !ast_strlen_zero(data)) {
+		if (value && !ast_strlen_zero(value)) {
+			setenv(data, value, 1);
+		} else {
+			unsetenv(data);
+		}
+	}
+}
+
+#ifndef BUILTIN_FUNC
+static
+#endif
+struct ast_custom_function env_function = {
+	.name = "ENV",
+	.synopsis = "Gets or sets the environment variable specified",
+	.syntax = "ENV(<envname>)",
+	.read = builtin_function_env_read,
+	.write = builtin_function_env_write,
+};