To free in-memory data that was created by an Xlib function, use
XFree().
Syntax
XFree(data)
void *data;
Arguments
data
Specifies the data that is to be freed.
Description
The
XFree()
function is a general-purpose Xlib routine that frees the specified data.
You must use it to free any objects that were allocated by Xlib,
unless an alternate function is explicitly specified for the object.
A NULL pointer cannot be passed to this function.