The programming examples in this section shows the usage of XFN APIs to perform the following operations:
The example below shows XFN operations to list a context.
| #include <stdio.h>
#include <xfn/xfn.h>
#include <string.h>
#include <stdlib.h>
/*
 This routine returns the list of names
 bound under the given context (ctx_name).
 Examples of ctx_name are "user", "thisorgunit/service",
	host/alto/service, user/jsmit/service/calendar, etc.,
*/
typedef struct fns_listing {
	char *name;
	struct fns_listing *next;
} fns_listing;
fns_listing *
fns_list_names(const char *ctx_name)
{
	FN_status_t *status;
	FN_ctx_t *initial_context;
	FN_composite_name_t *context_name;
	FN_namelist_t *name_list;
	FN_string_t *name;
	unsigned int stat;
	fns_listing *head = 0, *current, *prev;
	int no_names = 0;
	status = fn_status_create();
	/* Obtain the initial context */
	initial_context = fn_ctx_handle_from_initial(0, status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to obtain intial context\n");
		return (0);
	}
	context_name = fn_composite_name_from_str((unsigned char *)
                  ctx_name);
	/* FNS call to list names */
	name_list = fn_ctx_list_names(initial_context, context_name,
               status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to list names\n");
		return (0);
	}
	/* Obtain the names individually */
	while (name = fn_namelist_next(name_list, status)) {
		no_names++;
		current = (fns_listing *) malloc(sizeof(fns_listing));
		current->name = (char *)
		 malloc(strlen((char *) fn_string_str(name, &stat)) + 1);
		strcpy(current->name, (char *) fn_string_str(name, &stat));
		current->next = 0;
		if (head) {
			prev->next = current;
			prev = current;
		} else {
			head = current;
			prev = current;
		}
		fn_string_destroy(name);
	}
	fn_namelist_destroy(name_list);
	fn_status_destroy(status);
	fn_ctx_destroy(initial_context);
	return (head); | 
The example below shows how to create a binding.
| #include <stdio.h>
#include <xfn/xfn.h>
#include <string.h>
/*
 This routine creates a binding with a name provided by "name"
 and having a reference type "reference_type" and address type
 "address_type".
 An example of using the function could be:
	 fns_create_bindings(
	 "user/jsmith/service/calendar",
	 "onc_calendar",
	 "onc_cal_str",
	 "jsmith&calserver");
*/
int fns_create_bindings(
 char *name,
 char *reference_type,
 char *address_type,
 char *data)
{
	int return_status;
	FN_composite_name_t *binding_name;
	FN_identifier_t ref_id, addr_id;
	FN_status_t *status;
	FN_ref_t *reference;
	FN_ref_addr_t *address;
	FN_ctx_t *initial_context;
	/* Obtain the initial context */
	status = fn_status_create();
	initial_context = fn_ctx_handle_from_initial(0, status);
	/* Check status for any error messages */
	if ((return_status = fn_status_code(status)) != FN_SUCCESS) {
		fprintf(stderr, "Unable to obtain the initial context\n");
		return (return_status);
	}
	/* Get the composite name for the printer name */
	binding_name = fn_composite_name_from_str((unsigned char *) name);
	/* Construct the Address */
	addr_id.format = FN_ID_STRING;
	addr_id.length = strlen(address_type);
	addr_id.contents = (void *) address_type;
	address = fn_ref_addr_create(&addr_id,
		strlen(data), (const void *) data);
	/* Construct the Reference */
	ref_id.format = FN_ID_STRING;
	ref_id.length = strlen(reference_type);
	ref_id.contents = (void *) reference_type;
	reference = fn_ref_create(&ref_id);
	/* Add Address to the Reference */
	fn_ref_append_addr(reference, address);
	
	/* Create a binding */
	fn_ctx_bind(initial_context, binding_name, reference, 0, status);
	/* Check the error status and return */
	return_status = fn_status_code(status);
	fn_composite_name_destroy(binding_name);
	fn_ref_addr_destroy(address);
	fn_ref_destroy(reference);
	fn_ctx_destroy(initial_context);
	return (return_status);
} | 
The examples below show techniques to list and work with attributes of an object.
The example below shows how to list the attributes of an object.
| #include <stdio.h>
#include <xfn/xfn.h>
/*
 This routine prints all the attributes associated
 with the named object to the standard output.
 Examples of using the function:
 	fns_attr_list("user/jsmith");
	fns_attr_list("thisorgunit/service/printer/color");
*/
void fns_attr_list(const char *name)
{
	FN_composite_name_t *name_comp;
	const FN_identifier_t *identifier;
	FN_attribute_t *attribute;
	const FN_attrvalue_t *values;
	char *id, *val;
	FN_multigetlist_t *attrset;
	void *ip;
	FN_status_t *status;
	FN_ctx_t *initial_context;
	name_comp = fn_composite_name_from_str((unsigned char *) name);
	status = fn_status_create();
	/* Obtain the initial context */
	initial_context = fn_ctx_handle_from_initial(0, status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to obtain intial context\n");
		return;
	}
	/* Obtain all the attributes */
	attrset = fn_attr_multi_get(initial_context, name_comp, 0, 0,
            status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to obtain attributes\n");
		return;
	}
	/* List all attributes */
	while (attribute = fn_multigetlist_next(attrset, status)) {
		identifier = fn_attribute_identifier(attribute);
		switch(identifier->format) {
		case FN_ID_STRING:
			id = (char *) malloc(identifier->length + 1);
			memcpy(id, identifier->contents, identifier->length);
			id[identifier->length] = '\0';
			printf("Attribute Identifier: %s", id);
			free(id);
			break;
		default:
			printf("Attribute of non-string format\n\n");
			continue;
		}
		for (values = fn_attribute_first(attribute, &ip);
		 values != NULL;
		 values = fn_attribute_next(attribute, &ip)) {
			val = (char *) malloc(values->length + 1);
			memcpy(val, values->contents, values->length);
			val[values->length] = '\0';
			printf("Value: %s", val);
			free(val);
		}
		fn_attribute_destroy(attribute);
		printf("\n");
	}
	fn_multigetlist_destroy(attrset);
	fn_ctx_destroy(initial_context);
	fn_status_destroy(status);
	fn_composite_name_destroy(name_comp);
} | 
The example below shows how to add, delete, or modify an object's attributes.
| #include <stdio.h>
#include <xfn/xfn.h>
/*
 This routine modifies an attribute associated
 with the named object. The modify operation supported are:
 	FN_ATTR_OP_ADD
 FN_ATTR_OP_ADD_EXCLUSIVE
 FN_ATTR_OP_REMOVE
 FN_ATTR_OP_ADD_VALUES
 FN_ATTR_OP_REMOVE_VALUES
 The function assumes the attribute values to be strings.
 Examples of using the function:
 The following function add an attribute of identifier "realname"
 with value "James Smith" to the user object "user/jsmith".
 	fns_attr_modify(
		"user/jsmith",
		"realname",
		"James Smith",
		FN_ATTR_OP_ADD);
 The following function removes an attribute of identifier 
 "location" from the printer object 
 "thisorgunit/service/printer/color".
 	fns_attr_modify(
		"thisorgunit/service/printer/color",
		"location",
		NULL,
		FN_ATTR_OP_REMOVE);
*/
static const char *attr_id_syntax = "fn_attr_syntax_ascii";
void fns_attr_modify(const char *name,
	const char *attr_id,
	const char *attr_value,
	unsigned int operation)
{
	FN_composite_name_t *name_comp;
	FN_identifier_t identifier, syntax;
	FN_attrvalue_t *values;
	FN_attribute_t *attribute;
	FN_status_t *status;
	FN_ctx_t *initial_context;
	name_comp = fn_composite_name_from_str((unsigned char *) name);
	status = fn_status_create();
	/* Obtain the initial context */
	initial_context = fn_ctx_handle_from_initial(0, status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to obtain intial context\n");
		return;
	}
	/* Create the attribute to be added */
	/* First, the identifier */
	identifier.format = FN_ID_STRING;
	identifier.length = strlen(attr_id);
	identifier.contents = (void *) strdup(attr_id);
	/* Second, the syntax */
	syntax.format = FN_ID_STRING;
	syntax.length = strlen(attr_id_syntax);
	syntax.contents = (void *) strdup(attr_id_syntax);
	/* Third, the attribute value */
	if (attr_value) {
		values = (FN_attrvalue_t *) malloc(sizeof(FN_attrvalue_t));
		values->length = strlen(attr_value);
		values->contents = (void *) strdup(attr_value);
	} else
		values = NULL;
	/* Fourth, create the attribute */
	attribute = fn_attribute_create(&identifier, &syntax);
	/*Fifth, add the attribute value */
	if (values)
		fn_attribute_add(attribute, values, 0);
	
	/* Perform the XFN operation */
	fn_attr_modify(initial_context, name_comp, operation, attribute, 0,
status);
	if (!fn_status_is_success(status))
		fprintf(stderr, "Unable to perform attribute operation\n");
	fn_ctx_destroy(initial_context);
	fn_status_destroy(status);
	fn_composite_name_destroy(name_comp);
	fn_attibute_destroy(attribute);
	free(identifier.contents);
	free(syntax.contents);
	if (values) {
		free(values->contents);
		free(values);
 ]
] | 
The example below shows how to search for objects in a context with a specific attribute identifier and value.
| #include <stdio.h>
#include <xfn/xfn.h>
#include <string.h>
#include <stdlib.h>
/*
 This routine searchs for objects in a context
 which has the specified attribute identifier and value.
*/
typedef struct fns_search_results {
	char *name;
	struct fns_search_results *next;
} fns_search_results;
static const char *attr_id_syntax = "fn_attr_syntax_ascii";
fns_search_results *
fns_attr_search(const char *name,
	const char *attr_id,
	const char *attr_value)
{
	FN_status_t *status;
	FN_ctx_t *initial_context;
	FN_composite_name_t *context_name;
	FN_searchlist_t *search_list;
	FN_string_t *search_name;
	FN_attribute_t *attribute;
	FN_attrset_t *attrset;
	FN_identifier_t identifier, syntax;
	FN_attrvalue_t *values;
	unsigned stat;
	fns_search_results *head = 0, *current, *prev;
	int no_names = 0;
	context_name = fn_composite_name_from_str((unsigned char *) name);
	status = fn_status_create();
	initial_context = fn_ctx_handle_from_initial(0, status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to obtain intial context\n");
		return (0);
	}
	/* Construnct the attrset with attributes to be searched */
	/* First, the identifier */
	identifier.format = FN_ID_STRING;
	identifier.length = strlen(attr_id);
	identifier.contents = (void *) strdup(attr_id);
	/* Second, the syntax */
	syntax.format = FN_ID_STRING;
	syntax.length = strlen(attr_id_syntax);
	syntax.contents = (void *) strdup(attr_id_syntax);
	/* Third, the attribute value */
	values = (FN_attrvalue_t *) malloc(sizeof(FN_attrvalue_t));
	values->length = strlen(attr_value);
	values->contents = (void *) strdup(attr_value);
	/* Fourth, create the attribute */
	attribute = fn_attribute_create(&identifier, &syntax);
	/* Fifth, add the attribute value */
	fn_attribute_add(attribute, values, 0);
	/* Sixth, create attrset, and add the attribute */
	attrset = fn_attrset_create();
	fn_attrset_add(attrset, attribute, 0);
	search_list = prelim_fn_attr_search(initial_context,
	 context_name, attrset, 0, 0, status);
	if (!fn_status_is_success(status)) {
		fprintf(stderr, "Unable to list names\n");
		return (0);
	}
	while (search_name = prelim_fn_searchlist_next(search_list,
	 0, 0, status)) {
		no_names++;
		current = (fns_search_results *) 
    malloc(sizeof(fns_search_results));
		current->name = (char *)
		 malloc(strlen((char *) fn_string_str(search_name, &stat)) + 1);
		strcpy(current->name, (char *) fn_string_str(search_name, &stat));
		current->next = 0;
		if (head) {
			prev->next = current;
			prev = current;
		} else {
			head = current;
			prev = current;
		}
		fn_string_destroy(search_name);
	}
	fn_searchlist_destroy(search_list);
	fn_status_destroy(status);
	fn_ctx_destroy(initial_context);
	fn_attrset_destroy(attrset);
	fn_attribute_destroy(attribute);
	free(identifier.contents);
	free(syntax.contents);
	free(values->contents);
	free(values);
	return (head);
} |