#!F-adobe-helvetica-medium-r-normal--18*
#!N
#!CNavyBlue #!N #!Rinitex Initialization
and Exit #!N #!EC #!N #!N These routines enable an application
to initiate and terminate connections with Data Explorer. DXLStartDX establishes a
connection #!F-adobe-times-bold-r-normal--18* *conn #!EF for a Data Explorer instance. It is
through this connection that information is sent and received during a
Data Explorer session. #!N #!I0 #!N #!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18*
void DXLCloseConnection(DXLConnection *conn) #!EF #!EF #!I50 #!N Closes the connection to
Data Explorer ( #!F-adobe-times-bold-r-normal--18* *conn #!EF ) and frees the memory
allocated to #!F-adobe-times-bold-r-normal--18* *conn #!EF but does not terminate the Data
Explorer session. #!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* DXLConnection *DXLConnectToRunningServer(int port, const
char *host) #!EF #!EF #!I50 #!N This routine is used primarily
for debugging purposes, to connect to a server (i.e., dxexec or
dxui) that has already been started externally and is waiting for
a connection (see -exonly and -appPort options). The routine creates a
connection between the calling application and Data Explorer at the specified
port on the specified host. #!N #!N The parameter #!F-adobe-times-bold-r-normal--18* port
#!EF must be greater than or equal to zero. If #!F-adobe-times-bold-r-normal--18*
host #!EF is specified as NULL, the function uses "localhost." #!N
#!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* DXLError DXLExitDX(DXLConnection *conn) #!EF #!EF #!I50 #!N
Closes the connection to Data Explorer ( #!F-adobe-times-bold-r-normal--18* *conn #!EF )
and terminates the Data Explorer session. Returns OK or ERROR. #!N
#!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* int DXLGetSocket(DXLConnection *conn) #!EF #!EF #!I50 #!N
Returns the socket number associated with connection #!F-adobe-times-bold-r-normal--18* *conn #!EF .
#!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* DXLError DXLInitializeXMainLoop(XtAppContext app, DXLConnection *conn) #!EF
#!EF #!I50 #!N Initializes the X11 window system so that calls
to XtAppMainLoop will cause messages to be processed. (See #!Lmsgsys,dxall1147 h Messaging System #!EL .)
#!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* int DXLSetMessageDebugging(DXLConnection *c, int on) #!EF
#!EF #!I50 #!N Specifies the on-off status of message debugging. If
it is enabled, messages are printed to the terminal window as
they are sent or received. The return value identifies the previous
state of message debugging. #!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* void DXLSetSynchronization(DXLConnection
*conn, const int onoff) #!EF #!EF #!I50 #!N Sets the synchronization
status of the connection to Data Explorer. When #!F-adobe-times-bold-r-normal--18* onoff #!EF
is set to 1, the connection is synchronized; when set to
0, it is not. With the connection synchronized, routines wait for
a response from the "server" (i.e., UI or exec) after a
message is sent. For example, if synchronization has been turned on,
a call to DXLSetValue will not return until the server has
processed the set value. #!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* DXLConnection *DXLStartDX(const
char *string, char *host) #!EF #!EF #!I50 #!N Starts Data Explorer
and creates a connection to it. The parameter #!F-adobe-times-bold-r-normal--18* *string #!EF
is the command that would be used to start Data Explorer
at the command line. For example, #!F-adobe-times-bold-r-normal--18* string #!EF could be:
#!CForestGreen #!N #!N #!F-adobe-courier-bold-r-normal--18* #!N dx -image -mdf user.mdf #!EF #!N
#!N #!EC #!N #!N Note that you must specify either -image,
-edit, or -menubar in order to bypass the Data Explorer Startup
window. It is not possible to use DXLStartDX to start Data
Explorer via the Startup window. The parameter #!F-adobe-times-bold-r-normal--18* *host #!EF is
the name of the host on which Data Explorer is to
be run. If specified as NULL, the local host is assumed.
#!N #!N The routine returns a pointer to a DXLConnection on
success or it returns NULL and sets an error code (available
in the global variable #!F-adobe-times-bold-r-normal--18* errno #!EF ). The connection structure,
specified by #!CForestGreen #!N #!N #!F-adobe-courier-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* #!N typedef struct DXLConnection
DXLConnection; #!EF #!EF #!N #!N #!EC #!N #!N is the primary
structure used by DXLink for maintaining information about the connection to
the server. This DXLConnection is passed to most DXLink routines to
indicate the relevant server connection. #!N #!N To start the Data
Explorer executive and connect DXLink to it, you might issue the
following call: #!CForestGreen #!N #!N #!F-adobe-courier-bold-r-normal--18* #!N DXLStartDX("dx -cache off -exonly");
#!EF #!N #!N #!EC #!N #!N The -exonly flag causes the
executive to start up and to wait for a connection from
DXLink. It is therefore required when connecting to the executive. Note
that the "-script" option should not be used, as it causes
the executive to start up in script mode, which requires commands
typed directly at a prompt, bypassing the message system. #!N #!N
Similarly, a connection to the Data Explorer user interface can be
initiated with the command: #!N #!N DXLStartDX("dx -edit -mdf my.mdf -image");
#!N #!I0 #!N #!F-adobe-times-bold-r-normal--18* #!F-adobe-times-bold-r-normal--18* void DXLSetBrokenConnectionCallback(DXLConnection *conn, #!EF void (*proc)(DXLConnection
*, void *), void *data); #!EF #!I50 #!N Allows the application
to install a routine to be called when the connection to
Data Explorer is broken. #!I0 #!N #!N #!N #!N #!N #!F-adobe-times-medium-i-normal--18*
Next Topic #!EF #!N #!N #!Lmsgsys,dxall1147 h Messaging System #!EL #!N #!F-adobe-times-medium-i-normal--18* #!N