ircg_who() will request a list of users
whose nickname is matching mask on connected
network connection. The optional parameter
ops_only will shrink the list to server
operators only.
The answer is sent to the output defined by ircg_set_file() or ircg_set_current(). 如果成功则返回 TRUE，失败则返回 FALSE。
See also: ircg_set_file(), and ircg_set_current().