查看erlang已经注册的原子

shijiang1130

2> rp(registered()).
[application_controller,mnesia_event,user_drv,error_logger,
mnesia_tm,mnesia_controller,standard_error,
mnesia_checkpoint_sup,global_group,mnesia_sup,mnesia_subscr,
mnesia_snmp_sup,standard_error_sup,kernel_safe_sup,
erl_prim_loader,mnesia_recover,mnesia_monitor,mnesia_locker,
init,rex,mnesia_late_loader,user,mnesia_kernel_sup,
kernel_sup,inet_db,global_name_server,code_server,
file_server_2]
ok
3>

shijiang1130

(a@127.0.0.1)22> register(my_aton,self()).
true
(a@127.0.0.1)23> rp(registered()).        
[user_drv,mnesia_recover,standard_error,error_logger,
mnesia_monitor,global_group,mnesia_locker,kernel_safe_sup,
mnesia_late_loader,auth,mnesia_kernel_sup,my_aton,
'ssh_system_"win"_22_sup',erl_prim_loader,net_kernel,
erl_epmd,ssh_sup,mnesia_event,mnesia_tm,mnesia_controller,
rex,mnesia_checkpoint_sup,init,net_sup,kernel_sup,user,
inet_db,mnesia_sup,global_name_server,code_server,
standard_error_sup,mnesia_subscr,mnesia_snmp_sup,
file_server_2,sshd_sup,application_controller,sshc_sup]
ok
(a@127.0.0.1)24> erl      
erl_distribution    erl_epmd            erl_eval            
erl_internal        erl_lint            erl_parse           
erl_prim_loader     erl_scan            erlang              

(a@127.0.0.1)24> erlang:whereis(my_aton).
<0.102.0>
(a@127.0.0.1)25> erlang:un               
universaltime/0               universaltime_to_localtime/1  
universaltime_to_posixtime/1  unlink/1                     
unregister/1                  
(a@127.0.0.1)25> erlang:unregister(my_aton).
true
(a@127.0.0.1)26> rp(registered()).         
[user_drv,mnesia_recover,standard_error,error_logger,
mnesia_monitor,global_group,mnesia_locker,kernel_safe_sup,
mnesia_late_loader,auth,mnesia_kernel_sup,
'ssh_system_"win"_22_sup',erl_prim_loader,net_kernel,
erl_epmd,ssh_sup,mnesia_event,mnesia_tm,mnesia_controller,
rex,mnesia_checkpoint_sup,init,net_sup,kernel_sup,user,
inet_db,mnesia_sup,global_name_server,code_server,
standard_error_sup,mnesia_subscr,mnesia_snmp_sup,
file_server_2,sshd_sup,application_controller,sshc_sup]
ok
(a@127.0.0.1)27>

shijiang1130

https://github.com/uwiger/gproc

Gproc is a process dictionary for Erlang, which provides a number of useful features beyond what the built-in dictionary has:

Use any term as a process alias

Register a process under several aliases

Non-unique properties can be registered simultaneously by many processes

QLC and match specification interface for efficient queries on the dictionary

Await registration, let's you wait until a process registers itself

Atomically give away registered names and properties to another process

Counters, and aggregated counters, which automatically maintain the total of all counters with a given name

Global registry, with all the above functions applied to a network of nodes

shijiang1130

踀(a@127.0.0.1)32> global:register_name(aaaa,self()).
yes
(a@127.0.0.1)33>
(a@127.0.0.1)33>
(a@127.0.0.1)33> global:registered_names().
[aaaa]
(a@127.0.0.1)34>

shijiang1130

(b@127.0.0.1)20> global:registered_names().
[aaaa]
(b@127.0.0.1)21> aaaa ! "ttt".            
** exception error: bad argument
     in operator  !/2
        called as aaaa ! "ttt"
(b@127.0.0.1)22> {aaaa} ! "ttt".
** exception error: bad argument
     in operator  !/2
        called as {aaaa} ! "ttt"
(b@127.0.0.1)23> aaaa ! "ttt".  
** exception error: bad argument
     in operator  !/2
        called as aaaa ! "ttt"
(b@127.0.0.1)24>