gtk-query-immodules-3.0
If called without arguments, it looks for modules in the GTK+ input method module path.
If called with arguments, it looks for the specified modules. The arguments may be absolute or relative paths.
Normally, the output of gtk-query-immodules-3.0 is written to libdir/gtk-3.0/3.0.0/immodules.cache, where GTK+ looks for it by default. If it is written to some other location, the GTK_IM_MODULE_FILE environment variable can be set to point GTK+ at the file.
--update-cache
libdir/gtk-3.0/3.0.0/immodules.cache
GTK_PATH
GTK_IM_MODULE_FILE