XConnectionNumber()XConnectionNumber()Name
XConnectionNumber, ConnectionNumber – get connection number or file
descriptor.
Synopsis
int XConnectionNumber(display)
Display *display;
Arguments
display Specifies a connection to an X server; returned from
XOpenDisplay().
Returns
The connection number.
DescriptionXConnectionNumber() returns the connection number for the specified
display. On a POSIX-conformant system, this is the file descriptor of
the connection.
The C language macro ConnectionNumber() is equivalent and slightly more
efficient.
Xlib - Macro Equivalents XConnectionNumber()