dx_open( )

Description | Cautions | Example | Errors | See Also

Name:	int dx_open(namep,oflags)
Inputs:	char *namep	pointer to device name to open
	int oflags	Reserved for future use
Returns:	>0 to indicate valid Dialogic device handle if successful
	-1 if failure
Includes:	srllib.h
	dxxxlib.h
Category:	Device Management

Description

The dx_open( ) function opens a Voice device and returns a unique Dialogic device handle to identify the device. All subsequent references to the opened device must be made using the handle until the device is closed. A device can be opened more than once by any number of processes.

NOTE:

The device handle returned by this function is Dialogic defined. It is not a standard Windows file descriptor. Any attempts to use Windows operating system commands such as read( ), write( ), or ioctl( ) will produce unexpected results.

By default, the maximum number of times you can simultaneously open the same channel in your application is set to 30 in the Windows Registry.

In applications that spawn child processes off a parent process, the device handle is not inheritable by the child process. Make sure devices are opened in the child process.

The function parameters are defined as follows:

Parameter	Description
namep	points to an ASCIIZ string that contains the name of the valid Dialogic device. These valid devices can be either boards or channels.
oflags	is reserved for future use. This parameter should be set to NULL.

Cautions

Do not use the Windows open( ) function to open a Voice device. Unpredictable results will occur.

Example

#include <srllib.h>  
#include <dxxxlib.h>  
#include <windows.h>  
main()  
{  
   int chdev;        /* channel descriptor */  
   .  
   .  
   .  
   /* Open Channel */  
   if ((chdev = dx_open("dxxxB1C1",NULL)) == -1) {  
     /* process error */  
   }  
   .  
   .  
}

Errors

If this function returns -1 to indicate failure, a system error has occurred; use dx_fileerrno( ) to obtain the system error value. Refer to the dx_fileerrno( ) function for a list of the possible system error values.

See Also

• dx_close( )

Click here to contact Dialogic Customer Engineering