set | grep [A-Za-z_]*\(\)

__expand_tilde_by_ref () 
__get_cword_at_cursor_by_ref () 
_available_interfaces () 
_cd () 
_cd_devices () 
_command () 
_command_offset () 
_complete_as_root () 
_completion_loader () 
_configured_interfaces () 
_count_args () 
_dvd_devices () 
_expand () 
_filedir () 
_filedir_xspec () 
_fstypes () 
_get_comp_words_by_ref ()
_get_cword () 
_get_first_arg () 
_get_pword () 
_gids () 
_have () 
_init_completion () 
_installed_modules () 
_ip_addresses () 
_kernel_versions () 
_known_hosts () 
_known_hosts_real () 
_longopt () 
_mac_addresses () 
_minimal () 
_modules () 
_ncpus () 
_parse_help () 
_parse_usage () 
_pci_ids () 
_pgids () 
_pids () 
_pnames () 
_quote_readline_by_ref () 
_realcommand () 
_rl_enabled () 
_root_command () 
_service () 
_services () 
_shells () 
_signals () 
_split_longopt () 
...  и т.д.