Comtrol API (6508) for the MS-DOS - Manual (Page 27)

27 API Functions
aaInit
aaInit
Executes controller and API initialization.
aaInit()
unsigned int
NO_ERR if no initialization
errors
ERR_ALLOCDEV if it can not
allocate device
structure
ERR_CTLINIT if controller
initialization
error
ERR_CHANINIT if channel
initialization
error
ERR_DEVSIZE if invalid number
of devices found
ERR_CTLSIZE if invalid number
of controllers
found
This function must be called once before calling any
other
API function except aaInstallCtrlCHandler(). The
controller initialization parameters is obtained from
the configuration file given by environment variable
ROCKETCFG .
Once aaInit() has been called, aaExit() must be called
before exiting the application program.
If the application program can be exited using the
CTRL+C or CTRL+BREAK keys, then the default DOS
CTRL+C handler must be replaced with a handler that
calls aaExit(). You can use the aaInstallCtrlCHandler()
function can be used for this purpose.
Function
Purpose
Call
Return
Comments
Warning
aaInstallCtrlCHandler
Installs a handler for the CTRL+C key interrupt.
aaInstallCtrlCHandler()
void
This function replaces the existing CTRL+C (interrupt
23H) handler with a handler that performs the
following actions:
1.
Calls aaExit().
2. Sets the carry flag to signal DOS to terminate the
application.
3. Executes a far return.
DOS restores the original CTRL+C handler when
terminating the application.
aaInstallCtrlCHandler() is the only
API function that can
be called before calling aaInit(). If you plan on using the
aaInstallCtrlCHandler() function, we recommend calling
it either immediately before or immediately after the
call to the aaInit() function.
If you want different
CTRL+C processing, you must
write and install your own custom CTRL+C handler.
Refer to the Microsoft MS-DOS Programmer's Reference
for more information. To aid in writing your own
handler, the source code for aaInstallCtrlCHandler() and
the handler it installs are given below:
void aaInstallCtrlCHandler(void)
{
dos_setvect(0x23,(void (interrupt far
*)())aaCtrlCIntHandler);
}
void far aaCtrlCIntHandler(void)
{
aaExit();
asm stc;
}
If the application program can be exited using the
CTRL+C or CTRL+BREAK keys, then the default DOS
CTRL+C handler must be replaced with a handler that
calls aaExit(). You can use the aaInstallCtrlCHandler()
function for this purpose.
Function
Purpose
Call
Return
Comments
Warning