Set x window title from within emacs

I start emacs with the —title option which sets the window title at the top of the window. Can this be done from within emacs? I would like to set it to the current active buffer.

The default value should show the current buffer. In case you want to change it: `C-h v frame-title-format` frame-title-format is a variable defined in `src/xdisp.c'. Its value is "%b" Template for displaying the title bar of visible frames. (Assuming the window manager supports this feature.)

Thanks. I tried this and the file name/buffer is correctly show on the lower bar but not the man window at the top. Gnome/Ubuntu.

Thanks, this does indeed work.

Does set-frame-name work?

I did not try that, frame-title-format worked.

emacs --name <custom_name>