isc_version()

Returns database implementation and version information.

Syntax

 int isc_version(
 isc_db_handle *db_handle,
 isc_callback function_name,
 void *user_arg);

Parameter	Type	Description
`db_handle`	`isc_db_handle *`	Pointer to a database handle set by a previous call to `isc_attach_database`(). `db_handle` returns an error in `status_vector` if it is `NULL`.
`function_name`	`isc_callback`	Pointer to a function to call with the relevant information. Passing a NULL pointer in C programs calls `printf()`.
`user_arg`	`void *`	An application-specified parameter to pass as the first of two arguments to `function_name`.

Description

isc_version() determines the database implementation and on-disk structure (ODS) version numbers for the database specified by db_handle. It passes this information in two separate calls to the callback function pointed to by function_name.

function_name should point to an application function that takes two arguments: a void pointer, user_arg, and a char pointer. Applications can pass any kind of parameter desired in user_arg.

isc_version() makes two calls to function_name. First it determines the database implementation number, builds a string containing the information, and calls function_name with user_arg, and a pointer to the string containing the implementation number in the following format:

<implementation>(<class>), version "<version>"

where:

implementation is a text string, such as “InterBase/NT”.
class is a text string specifying the implementation class, such as “access method”.
version is a version identification string, such as “8.0”. Note that InterBase 2007 is equivalent to version 8.0 of the InterBase code, so use 8.0 for this call.
The callback function specified by function_name is free to do with this information what it pleases.

After the callback function returns control to isc_version(), isc_version() builds a new string containing the ODS major and minor version numbers, then calls function_name a second time with user_arg, and a pointer to the string containing the ODS version number in the following format:

on disk structure version <ods_major_num>.<ods_minor_num>

where:

ods_major_num is the major ODS number. A server can always access a database that has the same major ODS as the server. When possible, CodeGear ensures that InterBase servers can access databases that are one major ODS older as well.
ods_minor_num is the minor ODS number. Differences in the minor ODS number do not affect database access.

Tip: If a NULL pointer is passed for function_name, isc_version() sets function_name to point to the C printf() function.

Examples

The following code fragment calls isc_version() with a NULL callback function:

#include <ibase.h>
. . .
int ret;
. . .
ret = isc_version(&db1, NULL, "\t%s\n");

Return value

If successful, isc_version() returns 0. Otherwise, it returns a nonzero value.

Advance To:

isc_wait_for_event()