XSaveContext, XFindContext, XDeleteContext, XUniqueContext − associative look-up routines


int XSaveContext(Display *display, XID rid, XContext context, XPointer data);

int XFindContext(Display *display, XID rid, XContext context, XPointer *data_return);

int XDeleteContext(Display *display, XID rid, XContext context);

XContext XUniqueContext(void);



Specifies the context type to which the data belongs.


Specifies the data to be associated with the window and type.


Returns the data.


Specifies the connection to the X server.


Specifies the resource ID with which the data is associated.


If an entry with the specified resource ID and type already exists, XSaveContext overrides it with the specified context. The XSaveContext function returns a nonzero error code if an error has occurred and zero otherwise. Possible errors are XCNOMEM (out of memory).

Because it is a return value, the data is a pointer. The XFindContext function returns a nonzero error code if an error has occurred and zero otherwise. Possible errors are XCNOENT (context-not-found).

The XDeleteContext function deletes the entry for the given resource ID and type from the data structure. This function returns the same error codes that XFindContext returns if called with the same arguments. XDeleteContext does not free the data whose address was saved.

The XUniqueContext function creates a unique context type that may be used in subsequent calls to XSaveContext.


Xlib − C Language X Interface


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