Name
bif_arg
,
bif_array_arg
,
bif_array_or_null_arg
,
bif_bin_arg
,
bif_double_arg
,
bif_entity_arg
,
bif_float_arg
,
bif_long_arg
,
bif_long_or_char_arg
,
bif_string_arg
,
bif_string_or_null_arg
,
bif_string_or_wide_or_null_arg
,
bif_strses_arg
— Get parameters for built in function
Synopsis
caddr_t
bif_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_array_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_array_or_null_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_bin_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_double_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_entity_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_float_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_long_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_long_or_char_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_string_arg
(
|
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_string_or_null_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_string_or_wide_or_null_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
caddr_t
bif_strses_arg
(
|
caddr_t *
qst
, |
| |
state_slot_t **
args
, |
| |
int
nth
, |
| |
char *
func
); |
Description
The bif_...._arg functions are used in the Virtuoso shared object. They allow
customization of the Virtuoso server.
They are written in C code, and linked with the Virtuoso shared object.
The _or_null_ variants of these functions represent the SQL null
value as a 00 pointer, even though getting the same argument with bif_arg()
would return a box with the DV_DB_NULL tag.
All number functions will coerce other types of numbers to the result type.
All array argument functions will accept any type of array. It is up to the
VSE itself to distinguish.
Virtuoso Server Extensions (VSEs) were formally referred to as Built-In Functions (BIFs).
Parameters
nth
which argument to retrieve (zero indexed).
func
name of calling function. This will be printed in the SQL error message.
Return Values
On success, return a valid pointer to the data retrieved, or NULL.
A SQL error is generated if the datatype is not valid.
The bif_arg is the only function not to have validation of a data type.
The values returned by any of these belong to the query instance, and the bif
is not authorized to modify or free them.
Table 24.5. Return types
| Function
|
Type validated and returned
|
| bif_arg
|
Any type of data. (no data type check)
|
| bif_array_arg
|
string or array data
|
| bif_array_or_null_arg
|
string or array or NULL data
|
| bif_bin_arg
|
binary data
|
| bif_double_arg
|
double data
|
| bif_entity_arg
|
XML entity data
|
| bif_float_arg
|
float data
|
| bif_long_arg
|
long data
|
| bif_long_or_char_arg
|
long or character data
|
| bif_string_arg
|
string data
|
| bif_string_or_null_arg
|
string or null data
|
| bif_string_or_wide_or_null_arg
|
strings, widestrings or null data
|
| bif_strses_arg
|
string session data
|
Examples
Example 24.22. Creating a function my_length()
A function called
my_length
written by developers, may process
a string argument by making a call to
bif_string_arg
.
