ErcStartupFiles

After a server has been connected to and it has sent its welcome message of the day, or MOTD, ERC takes the first file it finds from the ‘erc-startup-file-list’ and loads it. The default value is '("~/.emacs.d/.ercrc.el" "~/.emacs.d/.ercrc" "~/.ercrc.el" "~/.ercrc" ".ercrc.el" ".ercrc"). Files ending in “.el” are loaded as lisp files, the other files are executed as IRC scripts. Only one of these files – the first one which is readable – will be used.

Note that the init file is only loaded once when you begin an erc process. It will not get loaded again if you become disconnected and are automatically reconnected to the server.

Byte Compiled Init Files

As ERC uses the ‘load’ function to eval its initialisation file, loading time can be decreased by byte-compiling the ERC init file. As Emacs first tries to load byte compiled versions (.elc) before source versions (.el), any byte compiled startup file needs to be byte-compiled again for every modification. To byte-compile an Emacs-Lisp file, simple use something like M-x byte-compile-file .ercrc.el. Don’t worry about this though, it’s not very important. And ERC init files tend to be quite small too.

You also might want to check out AutoRecompile.

Nice startup tricks

Menu

This will add an ERC item to the Tools menu. It uses EasyMenu.

    (require 'easymenu)
    (easy-menu-add-item  nil '("tools")
      ["IRC with ERC" erc t])

Connecting

Here’s what I do. Can be used non-interactively. --DamienElmes

    (defmacro de-erc-connect (command server port nick)
      "Create interactive command `command', for connecting to an IRC server. The
      command uses interactive mode if passed an argument."
      (fset command
             `(lambda (arg)
               (interactive "p")
               (if (not (= 1 arg))
                   (call-interactively 'erc)
                 (erc :server ,server :port ,port :nick ,nick)))))
    (autoload 'erc "erc" "" t)
    (de-erc-connect erc-opn "jordan.openprojects.net" 6666 "resolve")
    (de-erc-connect erc-aust "pacific.austnet.org" 6666 "resolve")

Call it with something like M-x erc-opn, C-u M-x erc-opn to get prompted.

AndreasFuchs took that one and modified it a bit, so it can now be used with a dircproxy (and also ezb over SSL) bouncer:

 (defmacro asf-erc-bouncer-connect (command server port nick ssl pass)
   "Create interactive command `command', for connecting to an IRC server. The
   command uses interactive mode if passed an argument."
   (fset command
         `(lambda (arg)
           (interactive "p")
	   (if (not (= 1 arg))
	       (call-interactively 'erc)
	     (let ((erc-connect-function ',(if ssl
					       'erc-open-ssl-stream
					     'open-network-stream)))
 	       (erc :server ,server :port ,port :nick ,nick :password ,pass))))))
 (asf-erc-bouncer-connect erc-opn "frost.feig.at" 57002 "antifuchs" nil "pass1")
 (asf-erc-bouncer-connect erc-ircnet "frost.feig.at" 57001 "antifuchs" nil "pass1")
 (asf-erc-bouncer-connect erc-ifs "joplin.ifs.tuwien.ac.at" 6667 "antifuchs" nil nil)
 ;; ssl connection:
 (asf-erc-bouncer-connect erc-ifs "joplin.ifs.tuwien.ac.at" 6667 "antifuchs" t nil)

To start up ERC with just one command, use this function:

 ;; fires up a new frame and opens your servers in there. You will need
 ;; to modify it to suit your needs.
 (defun my-irc ()
   "Start to waste time on IRC with ERC."
   (interactive)
   (select-frame (make-frame '((name . "Emacs IRC")
 			      (minibuffer . t))))
   (call-interactively 'erc-ircnet)
   (sit-for 1)
   (call-interactively 'erc-opn)
   (sit-for 1)
   (call-interactively 'erc-ifs))

Autojoin

The following code shouldn’t be necessary anymore, see the ErcAutoJoin module.

DavidSpreen: Well, other versions don’t work on netsplit-forced reconnects so I adapted his solution and added it to the ‘erc-after-connect’ hook:

    (defun myerc-join-channels (&rest channels)
      (mapc 'erc-join-channel channels))
    (defun myerc-autojoin-channels (server nick)
     (cond
      ((member erc-session-server '("irc.tu-ilmenau.de"
                                    "irc.uni-erlangen.de"))
        (myerc-join-channels "#kiel"
                             "+linux.de"
                             "#debian.de"))
       ((string= erc-session-server "irc.debian.org")
        (myerc-join-channels "#emacs" 
                             "#debian-devel"))))
    (add-hook 'erc-after-connect 'myerc-autojoin-channels)

Riastradh says: This would be nicer as a macro:

  (defmacro erc-autojoin (&rest args)
    `(add-hook 'erc-after-connect
       '(lambda (server nick)
          (cond
           ,@(mapcar (lambda (servers+channels)
                       (let ((servers (car servers+channels))
                             (channels (cdr servers+channels)))
                         `((member erc-session-server ',servers)
                           (mapc 'erc-join-channel ',channels))))
                     args)))))

And then that code above would be more concisely written as:

  (erc-autojoin
    (("irc.tu-ilmenau.de" "irc.uni-erlangen.de")
     "#kiel" "+linux.de" "#debian.de"))
    (("irc.debian.org") "#debian-devel"))

ERC