erc: Connecting
5.1 Connecting to an IRC Server
===============================
The easiest way to connect to an IRC server is to call ‘M-x erc’. If
you want to assign this function to a keystroke, the following will help
you figure out its parameters.
-- Function: erc
Select connection parameters and run ERC. Non-interactively, it
takes the following keyword arguments.
• SERVER
• PORT
• NICK
• PASSWORD
• FULL-NAME
That is, if called with the following arguments, SERVER and
FULL-NAME will be set to those values, whereas ‘erc-compute-port’,
‘erc-compute-nick’ and ‘erc-compute-full-name’ will be invoked for
the values of the other parameters.
(erc :server "irc.freenode.net" :full-name "Harry S Truman")
Server
------
-- Function: erc-compute-server &optional server
Return an IRC server name.
This tries a number of increasingly more default methods until a
non-‘nil’ value is found.
• SERVER (the argument passed to this function)
• The ‘erc-server’ option
• The value of the IRCSERVER environment variable
• The ‘erc-default-server’ variable
-- User Option: erc-server
IRC server to use if one is not provided.
Port
----
-- Function: erc-compute-port &optional port
Return a port for an IRC server.
This tries a number of increasingly more default methods until a
non-‘nil’ value is found.
• PORT (the argument passed to this function)
• The ‘erc-port’ option
• The ‘erc-default-port’ variable
-- User Option: erc-port
IRC port to use if not specified.
This can be either a string or a number.
Nick
----
-- Function: erc-compute-nick &optional nick
Return user’s IRC nick.
This tries a number of increasingly more default methods until a
non-‘nil’ value is found.
• NICK (the argument passed to this function)
• The ‘erc-nick’ option
• The value of the IRCNICK environment variable
• The result from the ‘user-login-name’ function
-- User Option: erc-nick
Nickname to use if one is not provided.
This can be either a string, or a list of strings. In the latter
case, if the first nick in the list is already in use, other nicks
are tried in the list order.
-- User Option: erc-format-nick-function
A function to format a nickname for message display
You can set this to ‘erc-format-@nick’ to display user mode prefix
(setq erc-format-nick-function 'erc-format-@nick)
-- User Option: erc-nick-uniquifier
The string to append to the nick if it is already in use.
-- User Option: erc-try-new-nick-p
If the nickname you chose isn’t available, and this option is
non-‘nil’, ERC should automatically attempt to connect with another
nickname.
You can manually set another nickname with the /NICK command.
Password
--------
-- User Option: erc-prompt-for-password
If non-‘nil’ (the default), ‘M-x erc’ prompts for a password.
If you prefer, you can set this option to ‘nil’ and use the
‘auth-source’ mechanism to store your password. For instance, if you
use ‘~/.authinfo’ as your auth-source backend, then put something like
the following in that file:
machine irc.example.net login "#fsf" password sEcReT
ERC also consults ‘auth-source’ to find any channel keys required for
the channels that you wish to autojoin, as specified by the variable
‘erc-autojoin-channels-alist’.
For more details, 
auth-source (auth)Top.
Full name
---------
-- Function: erc-compute-full-name &optional full-name
Return user’s full name.
This tries a number of increasingly more default methods until a
non-‘nil’ value is found.
• FULL-NAME (the argument passed to this function)
• The ‘erc-user-full-name’ option
• The value of the IRCNAME environment variable
• The result from the ‘user-full-name’ function
-- User Option: erc-user-full-name
User full name.
This can be either a string or a function to call.
Info Catalog
erc: Advanced Usage
erc: Sample Configuration