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This manual is for ERC 5.6.1 from GNU ELPA.
Copyright © 2005–2024 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover Texts being “A GNU Manual,” and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled “GNU Free Documentation License”.
(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and modify this GNU manual.”
All Emacs Lisp code contained in this document may be used, distributed, and modified without restriction.
Next: Getting Started, Previous: ERC, Up: ERC [Contents][Index]
ERC is a powerful, modular, and extensible IRC client for Emacs. It has been included in Emacs since 2006 (see History) and is also available on GNU ELPA.
IRC is short for Internet Relay Chat. When using IRC, you can communicate with other users on the same IRC network. There are many different networks—if you search for “IRC networks” in your favorite search engine, you will find up-to-date lists of IRC networks catering to various interests and topics.
To use IRC, you need an IRC client such as ERC. Using the client, you connect to an IRC server. Once you’ve done that, you will have access to all available channels on that server’s network. A channel is basically a chat room, and what you type in a channel will be shown to all other users in that channel. You can be in several channels at the same time—ERC will show each channel in its own buffer.
IRC channel names always begin with a ‘#’ character. For example, the Emacs channel on Libera.Chat is ‘#emacs’, and the ERC channel is ‘#erc’. Do not confuse them with the hashtags used on many social media platforms.
You can also send private messages to other IRC users on the same network, even if they are not in the same channels as you.
ERC comes with the following capabilities enabled by default.
Next: Keys Used in ERC, Previous: Introduction, Up: ERC [Contents][Index]
The command M-x erc will start ERC and prompt for the server to connect to. If you’re unsure of which server or network to connect to, we suggest starting with “irc.libera.chat”. There you will find the ‘#emacs’ channels where you can chat with other Emacs users, and if you’re having trouble with ERC, you can join the ‘#erc’ channel and ask for help there.
At some point in your ERC journey, you’ll inevitably want to change how the client looks and behaves. As with other Emacs applications, the typical place to store your settings is your init.el. If you would rather use the Customize interface, a good place to start is by running M-x customize-group RET erc RET. In particular, ERC comes with lots of modules that may be enabled or disabled; to select which ones you want, do M-x customize-variable RET erc-modules RET.
Next: Special Features, Up: Getting Started [Contents][Index]
This example ERC session describes how to connect to the ‘#emacs’ channel on Libera.Chat. Also worth checking out is Libera’s own introductory guide to IRC, https://libera.chat/guides/basics, which presents a more comprehensive overview without instructions specific to ERC.
Run M-x erc RET. Use ‘irc.libera.chat’ for the server and ‘6667’ for the port. Choose a nickname, and hit y when asked if you’d prefer to connect over TLS.
Switch to the Libera.Chat buffer if you’re not already there. ERC calls this a server buffer, and it must exist for the duration of the session. You will likely see some messages about “ident”, authentication, and the like, followed by information describing the current server and the network.
In the server buffer, type /join #emacs RET at the prompt. ERC will create a new buffer called #emacs. If you’ve already configured ERC, you may need to switch to it manually. Once there, you will see the channel’s “topic” in the buffer’s header line (see (elisp)Header Lines) and a list of people currently in the channel. If you can’t see the full topic, mouse over it or type /topic RET at the prompt.
In order to access essential network features, like speaking in certain channels and participating in private conversations, you’ll likely have to “register” your nickname. To do so, switch to the Libera.Chat buffer and type /msg NickServ register ‘<password>’ ‘<email>’ RET, replacing ‘<password>’ and ‘<email>’ with your desired account password and contact email (both sans quotes). The server should tell you that the operation was successful. See the official Libera.Chat docs if you encounter problems.
In addition to creating an account, this process also “authenticates” you to the network’s “account services” system for the duration of the session. In other words, you’re now logged in. However, when you connect in the future, you’ll need to authenticate again by providing the same credentials somehow. When you’re finished with this walk through, see “Next Steps”, below, to learn some ways to do that.
Switch back to the #emacs buffer and type a message at the prompt, hitting RET once satisfied. Everyone in the channel will now see your message.
If you want to talk with someone in private, type /query ‘<nick>’ RET, replacing ‘<nick>’ with the their nickname. As before, with the server buffer, if this new query buffer doesn’t appear in the current window, you may have to switch to it. Regardless, its name should match ‘<nick>’. Once there, type something at the prompt and hit RET, and the other party will see it.
Keep in mind that if either party isn’t authenticated, you may not be able to converse at all. Also, depending on the network, certain social conventions may apply to the practice of direct messaging. As a general rule, queries should usually be reserved for personal matters rather than technical help, which can often benefit (and benefit from) a larger audience.
Try joining another channel, such as ‘#erc’, where ERC users and developers hang out (see Official IRC channels for more on the history of ‘#emacs’). For ideas on various options to customize, see Sample Configuration. To learn how ERC can authenticate you to the network automatically whenever you connect, see Authenticating via SASL. As always, if you encounter problems, see Getting Help and Reporting Bugs.
Previous: Sample Session, Up: Getting Started [Contents][Index]
ERC has some features that distinguish it from some IRC clients.
Every channel is put in a separate buffer. Several IRC servers may be connected to at the same time.
Private conversations are treated as channels, and are put into separate buffers in Emacs. We call these “query buffers”.
Some occurrences of words can be highlighted, which makes it easier to track different kinds of conversations.
ERC can notify you that certain users are online.
Channels can be hidden and conversation continue in the background. You are notified when something is said in such a channel that is not currently visible. This makes it easy to get Real Work done while still maintaining an IRC presence.
ERC can complete words upon hitting TAB, which eases the writing of nicknames in messages.
Past actions are kept in history rings for future use. To navigate a history ring, hit M-p to go backwards and M-n to go forwards.
Different channels and servers may have different language encodings.
multiple languages. Please contact the Emacs developers if you are interested in helping with the translation effort.
Users can load scripts (e.g., auto greeting scripts) when ERC starts up.
It is also possible to make custom IRC commands, if you know a little
Emacs Lisp. Just make an Emacs Lisp function and call it
erc-cmd-NEWCOMMAND, where NEWCOMMAND is the name of the
new command in capital letters.
If the connection goes away at some point, ERC will try to reconnect
automatically. If it fails to reconnect, and you want to try to
manually reestablish the connection at some later point, switch to an
ERC buffer and run the /RECONNECT command.
Next: Modules, Previous: Getting Started, Up: ERC [Contents][Index]
This is a summary of keystrokes available in every ERC buffer.
erc-bol)Go to beginning of line or end of prompt.
erc-send-current-line)Send the current line
completion-at-point or erc-button-next)If at prompt, complete the current word. Otherwise, move to the next link or button.
ispell-complete-word)Complete the given word, using ispell.
erc-bol)Go to beginning of line or end of prompt.
erc-switch-to-buffer)Use read-buffer to prompt for a ERC buffer to switch to.
erc-toggle-interpret-controls)Toggle interpretation of control sequences in messages.
erc-input-action)Interactively input a user action and send it to IRC.
erc-toggle-ctcp-autoresponse)Toggle automatic CTCP replies (like VERSION and PING).
erc-toggle-flood-control)Toggle use of flood control on sent messages.
erc-invite-only-mode)Turn on the invite only mode (+i) for the current channel.
erc-join-channel)Join channel. If point is at the beginning of a channel name, use that as default.
erc-go-to-log-matches-buffer)Interactively open an erc-log-matches buffer
erc-save-buffer-in-logs)Append buffer contents to the log file, if logging is enabled.
erc-channel-names)Run "/names #channel" in the current channel.
erc-get-channel-mode-from-keypress)Read a key sequence and call the corresponding channel mode function. After doing C-c C-o, type in a channel mode letter.
C-g means quit.
RET lets you type more than one mode at a time.
If l is pressed, erc-set-channel-limit gets called.
If k is pressed, erc-set-channel-key gets called.
Anything else will be sent to erc-toggle-channel-mode.
erc-part-from-channel)Part from the current channel and prompt for a reason.
erc-quit-server)Disconnect from current server after prompting for reason.
erc-remove-text-properties-region)Clears the region (start,end) in object from all colors, etc.
erc-set-topic)Prompt for a topic for the current channel.
erc-kill-input)Kill current input line using erc-bol followed by kill-line.
Next: Advanced Usage, Previous: Keys Used in ERC, Up: ERC [Contents][Index]
One way to add functionality to ERC is to customize which of its many modules are loaded.
You can do this by typing C-h v erc-modules RET and clicking
‘customize’ near the bottom of the resulting help buffer, where it
says “You can customize this variable.” When
removing a module outside of Customize, you may wish to ensure it’s
disabled by invoking its associated minor-mode toggle with a
nonpositive prefix argument, for example, C-u - M-x
erc-spelling-mode RET. Additionally, if you plan on loading
third-party modules that perform atypical setup on activation, you may
need to arrange for calling erc-update-modules in your init
file. Examples of such setup might include registering an
erc-before-connect hook, advising erc-open, and
modifying erc-modules itself. On Emacs 29 and greater, you can
also run erc-update-modules indirectly, via (setopt
erc-modules erc-modules).
The following is a list of available modules.
autoawaySet away status automatically
autojoinJoin channels automatically
bufbarList buffers belonging to a connection in a side window; part of
Custom group erc-status-sidebar
buttonButtonize URLs, nicknames, and other text
capab-identifyMark unidentified users on freenode and other servers supporting CAPAB.
command-indicatorEcho command lines for “slash commands”, like /JOIN #erc and /HELP join
completion (aka pcomplete)Complete nicknames and commands (programmable)
fillWrap long lines
identdLaunch an identd server on port 8113
irccontrolsHighlight or remove IRC control characters
keep-placeRemember your position in buffers
logSave buffers in logs
matchHighlight pals, fools, and other keywords
menuDisplay a menu in ERC buffers
netsplitDetect netsplits
nicksAutomatically colorize nicks
nickbarList participating nicks for the current target buffer in a side
window; part of Custom group erc-speedbar
noncommandsDon’t display non-IRC commands after evaluation
notifyNotify when the online status of certain users changes
notificationsSend you a notification when you get a private message, or your nickname is mentioned
pageProcess CTCP PAGE requests from IRC
querypollUpdate query participant data by continually polling the server
readonlyMake displayed lines read-only
replaceReplace text in messages
ringEnable an input history
saslEnable SASL authentication
scrolltobottomScroll to the bottom of the buffer
servicesIdentify to Nickserv (IRC Services) automatically
smileyConvert smileys to pretty icons
soundPlay sounds when you receive CTCP SOUND requests
spellingCheck spelling of messages
stampAdd timestamps to messages
trackTrack channel activity in the mode-line
truncateTruncate buffers to a certain size
unmorseTranslate morse code in messages
For various reasons, the following modules aren’t currently listed in
the Custom interface for erc-modules, but feel free to add them
explicitly. They may be managed by another module or considered more
useful when toggled interactively or just deemed experimental.
fill-wrapWrap long lines using visual-line-mode
keep-place-indicatorRemember your place in buffers with a visible reminder; activated
interactively or via something like erc-join-hook
services-regainAutomatically ask NickServ to reclaim your nick when reconnecting; experimental as of ERC 5.6
Note that some modules are essential to core IRC operations and thus
not listed above. You can nevertheless still remove these, but doing
so demands special precautions to avoid degrading the user experience.
At present, the only such module is networks, whose library ERC
always loads anyway.
All modules operate as minor modes under the hood, and some newer ones may be defined as buffer-local. These so-called “local modules” are a work in progress and their behavior and interface are subject to change. As of ERC 5.5, the only practical differences are as follows:
erc-sasl-mode, retain their values
across IRC sessions and override erc-module membership when
influencing module activation.
erc-modules via Customize not only
disables its mode but also kills its control variable in all ERC
buffers.
erc-sasl-mode and the complementary
erc-sasl-enable/erc-sasl-disable pairing, behave
differently than their global counterparts.
In target buffers, a local module’s activation state survives
“reassociation” by default, but modules themselves always have the
final say. For example, a module may reset all instances of itself in
its network context upon reconnecting. Moreover, the value of a mode
variable may be meaningless in buffers that its module has no interest
in. For example, the value of erc-sasl-mode doesn’t matter in
target buffers and may even remain non-nil after SASL has been
disabled for the current connection (and vice versa).
When it comes to server buffers, a module’s activation state only
persists for sessions revived via the automatic reconnection mechanism
or a manual ‘/reconnect’ issued at the prompt. In other words,
this doesn’t apply to sessions revived by an entry-point command, such
as erc-tls, because such commands always ensure a clean slate
by looking only to erc-modules. Although a session revived in
this manner may indeed harvest other information from a previous
server buffer, it simply doesn’t care which modules might have been
active during that connection.
Lastly, a local mode’s toggle command, like erc-sasl-mode, only
affects the current buffer, but its “non-mode” cousins, like
erc-sasl-enable and erc-sasl-disable, operate on all
buffers belonging to their connection (when called interactively).
And unlike global toggles, none of these ever mutates
erc-modules.
ERC loads internal modules in alphabetical order and third-party
modules as they appear in erc-modules. When defining your own
module, take care to ensure ERC can find it. An easy way to do that
is by mimicking the example in the doc string for
define-erc-module (also shown below). For historical reasons,
ERC falls back to requireing features. For example, if some
module my-module in erc-modules lacks a corresponding
erc-my-module-mode command, ERC will attempt to load the
library erc-my-module prior to connecting. If this fails, ERC
signals an error. Users defining personal modules in an init file
should (provide 'erc-my-module) somewhere to placate ERC.
Dynamically generating modules on the fly is not supported.
Some older built-in modules have a second name along with a second minor-mode toggle, which is just a function alias for its primary counterpart. For practical reasons, ERC does not define a corresponding variable alias because contending with indirect variables complicates bookkeeping tasks, such as persisting module state across IRC sessions. New modules should definitely avoid defining aliases without a good reason.
Some packages have been known to autoload a module’s definition
instead of its minor-mode command, which severs the link between the
library and the module. This means that enabling the mode by invoking
its command toggle isn’t enough to load its defining library. As
such, packages should only supply module-related autoload cookies with
an actual autoload form for their module’s minor-mode command,
like so:
;;;###autoload(autoload 'erc-my-module-mode "erc-my-module" nil t) (define-erc-module my-module nil "My doc string." ((add-hook 'erc-insert-post-hook #'erc-my-module-on-insert-post)) ((remove-hook 'erc-insert-post-hook #'erc-my-module-on-insert-post)))
As implied earlier, packages can usually omit such cookies entirely so long as their module’s prefixed name matches that of its defining library and the library’s provided feature.
Finally, packages have also been observed to run
erc-update-modules in top-level forms, forcing ERC to take
special precautions to avoid recursive invocations. Another
unfortunate practice is mutating erc-modules itself upon
loading erc, possibly by way of an autoload. Doing this tricks
Customize into displaying the widget for erc-modules
incorrectly, with built-in modules moved from the predefined checklist
to the user-provided free-form area.
Next: Getting Help and Reporting Bugs, Previous: Modules, Up: ERC [Contents][Index]
Next: Authenticating via SASL, Up: Advanced Usage [Contents][Index]
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.
Select connection parameters and run ERC. Non-interactively, it takes the following keyword arguments.
For example, calling the command like so
(erc :server "irc.libera.chat" :full-name "J. Random Hacker")
sets server and full-name directly while leaving the rest
up to functions like erc-compute-port. Note that some
arguments can’t be specified interactively. id, in particular,
is rarely needed (see Network Identifier).
To connect securely over an encrypted TLS connection, use M-x erc-tls.
Select connection parameters and run ERC over TLS. Non-interactively, it takes the following keyword arguments.
That is, if called in the following manner
(erc-tls :server "irc.libera.chat" :full-name "J. Random Hacker")
the command will set server and full-name accordingly,
while helpers, like erc-compute-nick, will determine other
parameters, and some, like client-certificate, will just be
nil.
To use a certificate with erc-tls, specify the optional
client-certificate keyword argument, whose value should be as
described in the documentation of open-network-stream: if
non-nil, it should either be a list where the first element is
the file name of the private key corresponding to a client certificate
and the second element is the file name of the client certificate
itself to use when connecting over TLS, or t, which means that
auth-source will be queried for the private key and the
certificate. Authenticating using a TLS client certificate is also
referred to as “CertFP” (Certificate Fingerprint) authentication by
various IRC networks.
Examples of use:
(erc-tls :server "irc.libera.chat" :port 6697
:client-certificate
'("/home/bandali/my-cert.key"
"/home/bandali/my-cert.crt"))
(erc-tls :server "irc.libera.chat" :port 6697
:client-certificate
`(,(expand-file-name "~/cert-libera.key")
,(expand-file-name "~/cert-libera.crt")))
(erc-tls :server "irc.libera.chat" :port 6697
:client-certificate t)
In the case of :client-certificate t, you will need to add a
line like the following to your authinfo file
(e.g. ~/.authinfo.gpg):
machine irc.libera.chat key /home/bandali/my-cert.key cert /home/bandali/my-cert.crt
See Help for users in Emacs auth-source Library, for more on the
.authinfo/.netrc backend of auth-source.
For other uses of auth-source throughout ERC, see ERC’s auth-source integration.
Return an IRC server name.
This tries a progressively greater number of default methods until a
non-nil value is found.
erc-server option
erc-default-server variable
IRC server to use if one is not provided.
Return a port for an IRC server.
This tries a progressively greater number of default methods until a
non-nil value is found.
erc-port option
erc-default-port variable
IRC port to use if not specified.
This can be either a string or a number.
Return user’s IRC nick.
This tries a progressively greater number of default methods until a
non-nil value is found.
erc-nick option
user-login-name function
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.
A boolean for including a channel member’s status prefix in their display name when they speak.
The string to append to the nick if it is already in use.
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.
Determine a suitable value to send as the first argument of the opening ‘USER’ IRC command by consulting the following sources:
erc-email-userid, assuming erc-anonymous-login
is non-nil
user-login-name
A permanent username value to send for all connections. It should be a string abiding by the rules of the network.
This parameter was traditionally meant to specify a server password to be sent along with the IRC ‘PASS’ command. However, such passwords aren’t widely used. Instead, networks typically expect them, when present, to convey other authentication information. In the case of account-services (a.k.a., “NickServ”) credentials, this typically involves a special syntax, such as ‘myuser:mypass’. IRC bouncers often do something similar but include a pre-configured network-ID component, for example, ‘bncuser/mynet:bncpass’.
In general, if you have not been asked by your network or bouncer to specify a repurposed server password, you should instead consider setting up ‘services’ or, preferably, ‘sasl’, both ERC modules (see Modules). In addition to performing network-account authentication, these obviate the need for this parameter completely, although both can optionally borrow it for their own purposes. (See SASL in ERC.)
If non-nil (the default), M-x erc and M-x erc-tls
prompt for a server password. This only affects interactive
invocations of erc and erc-tls.
If you prefer, you can set this option to nil and use the
auth-source facility to retrieve a server password, although hitting
RET at the prompt may achieve the same effect.
See ERC’s auth-source integration, for more.
Return user’s full name.
This tries a progressively greater number of default methods until a
non-nil value is found.
erc-user-full-name option
user-full-name function
User full name.
This can be either a string or a function to call.
ERC uses an abstract designation, called network context
identifier, for referring to a connection internally. While normally
derived from a combination of logical and physical connection
parameters, an ID can also be explicitly provided via an entry-point
command (like erc-tls). Use this in rare situations where ERC
would otherwise have trouble discerning between connections.
One such situation might arise when using multiple connections to the same network with the same nick but different (nonstandard) ‘device’ identifiers, which some bouncers may support. Another might be when mimicking the experience offered by popular standalone clients, which normally offer “named” persistent configurations with server buffers reflecting those names. Yet another use case might involve third-party code needing to identify a connection unequivocally, but in a human-friendly way suitable for UI components.
When providing an ID as an entry-point argument, strings and symbols make the most sense, but any reasonably printable object is acceptable.
Next: Sample Configuration, Previous: Connecting to an IRC Server, Up: Advanced Usage [Contents][Index]
If you’ve used SASL elsewhere, you can probably skip to the examples below. Otherwise, if you haven’t already registered with your network, please do so now, referring to the network’s own instructions for details. If you’re new to IRC and using a bouncer, know that you probably won’t be needing this for the client-to-bouncer connection.
When you’re ready to get started, add sasl to
erc-modules, like you would any other module. If unsure which
mechanism to choose, stick with the default of ‘PLAIN’.
Then try C-u M-x erc-tls RET, and give your account name
for the ‘user’ parameter and your account password for the
‘server password’.
The name of an SASL subprotocol type as a lowercase symbol. The value can be one of the following:
plain or scram (“password-based”)Here, “password” refers to your account password, which is usually
your ‘NickServ’ password. To make this work, customize
erc-sasl-user and erc-sasl-password or specify the
:user and :password keyword arguments when invoking
erc-tls.
external (via client TLS certificate)This works in conjunction with the :client-certificate keyword
offered by erc-tls. Just ensure you’ve registered your
fingerprint with the network beforehand. The fingerprint is usually a
SHA1 or SHA256 digest in either "normalized" or "openssl" forms. The
first is lowercase without delims (‘deadbeef’) and the second
uppercase with colon seps (‘DE:AD:BE:EF’). These days, there’s
usually a ‘CERT ADD’ command offered by NickServ that can
register you automatically if you issue it while connected with a
client cert. See client-certificate.
Additional considerations:
ecdsa-nist256p-challengeThis mechanism is quite complicated and currently requires the
external ‘openssl’ executable, so please use something else if at
all possible. Ignoring that, specify your key file (e.g.,
‘~/pki/mykey.pem’) as the value of erc-sasl-password, and
then configure your network settings. On servers running Atheme
services, you can add your public key with ‘NickServ’ like so:
ERC> /msg NickServ set property \
pubkey AgGZmlYTUjJlea/BVz7yrjJ6gysiAPaQxzeUzTH4hd5j
(You may be able to omit the ‘property’ subcommand.)
This should be your network account username, typically the same one
registered with nickname services. Specify this when your NickServ
login differs from the :user you’re connecting with.
See username parameter.
As noted elsewhere, the entry-point :password param was
originally intended for traditional “server passwords,” but these
aren’t really used any more (see password parameter). As such,
this option defaults to borrowing that parameter for its own uses,
thus allowing you to call erc-tls with :password set to
your NickServ password.
You can also set this to a nonemtpy string, and ERC will send that
when needed, no questions asked. Or, if you’d rather use auth-source,
set erc-sasl-auth-source-function to a function, and ERC will
perform an auth-source query instead. In all cases, ERC will prompt
you for input as a last resort.
Lastly, if your mechanism is ecdsa-nist256p-challenge, this
option should instead hold the file name of your key.
This is nearly identical to the other ERC ‘auth-source’ function
options (see auth-source functions) except that the default value
here is nil, meaning you have to set it to something like
erc-auth-source-search for queries to be performed. For
convenience, this module provides the following as a possible value:
Setting erc-sasl-auth-source-function to this function tells
ERC to use erc-sasl-password for the :host field when
querying auth-source, even if its value is the default
:password, in which case ERC knows to “resolve” it to
erc-session-password and use that as long as it’s
non-nil. Otherwise, ERC just defers to
erc-auth-source-search to determine the :host, along
with everything else.
As long as this option specifies a function, ERC will pass it the
“resolved” value of erc-sasl-user for the auth-source
:user param.
In the rarest of circumstances, a network may want you to specify a
specific role or assume an alternate identity. In most cases, this
happens because the server is buggy or misconfigured. If you suspect
such a thing, please contact your network operator. Otherwise, just
leave this set to nil.
(erc-tls :server "irc.libera.chat" :port 6697
:nick "aph"
:user "APHacker"
:password "changeme")
Here, after adding sasl to erc-modules via the Customize
interface, you authenticate to Libera.Chat using the ‘PLAIN’
mechanism and your NickServ credentials, ‘APHacker’ and
‘changeme’.
(setopt erc-sasl-mechanism 'external)
(erc-tls :server "irc.libera.chat" :port 6697 :nick "aph"
:client-certificate
'("/home/aph/my.key" "/home/aph/my.crt"))
You decide to switch things up and try out the ‘EXTERNAL’ mechanism. You follow your network’s instructions for telling NickServ about your client-certificate’s fingerprint, and you authenticate successfully.
# ~/.authinfo.gpg machine irc.libera.chat key /home/aph/my.key cert /home/aph/my.crt machine Example.Net login alyssa password sEcReT machine Example.Net login aph-bot password sesame
;; init.el
(defun my-erc-up (network)
(interactive "Snetwork: ")
(require 'erc-sasl)
(or (let ((erc-modules (cons 'sasl erc-modules)))
(pcase network
('libera
(let ((erc-sasl-mechanism 'external))
(erc-tls :server "irc.libera.chat"
:client-certificate t)))
('example
(let ((erc-sasl-auth-source-function
#'erc-sasl-auth-source-password-as-host))
(erc-tls :server "irc.example.net"
:user "alyssa"
:password "Example.Net")))))
;; Non-SASL
(call-interactively #'erc-tls)))
You’ve started storing your credentials with auth-source and have
decided to try SASL on another network as well. But there’s a catch:
this network doesn’t support ‘EXTERNAL’. You use
let-binding to work around this and successfully authenticate
to both networks. (Note that this example assumes you’ve removed
sasl from erc-modules globally and have instead opted to
add it locally when connecting to preconfigured networks.)
First and foremost, please know that ERC’s SASL offering is currently limited by a lack of support for proper IRCv3 capability negotiation. In most cases, this shouldn’t affect your ability to authenticate.
If you’re struggling, remember that your SASL password is almost
always your NickServ password. When in doubt, try restoring all SASL
options to their defaults and calling erc-tls with :user
set to your NickServ account name and :password to your
NickServ password. If you’re still having trouble, please contact us
(see Getting Help and Reporting Bugs).
As you try out different settings, keep in mind that it’s best to
create a fresh session for every change, for example, by calling
erc-tls from scratch. More experienced users may be able to
get away with cycling erc-sasl-mode and issuing a
‘/reconnect’, but that’s generally not recommended. Whatever the
case, you’ll probably want to temporarily disable
erc-server-auto-reconnect while experimenting.
Next: Integrations, Previous: Authenticating via SASL, Up: Advanced Usage [Contents][Index]
Here is an example configuration for ERC. Don’t panic if you aren’t familiar with ‘use-package’ or have no interest in learning it. For our purposes, it’s just a means of presenting configuration details in a tidy, standardized format. If it helps, just pretend it’s some make-believe, pseudo configuration language. And while the syntax below is easy enough to intuit and adapt to your setup, you may wish to keep the following in mind:
use-package “declaration” focuses on a library
“feature”, which is just a symbol you’d normally require in
your config.
:config section after loading
whatever library provides the declaration’s feature.
:custom or :custom-face section is
basically something you’d find in your custom-file.
The following would typically go in your init file. Experienced users may opt to keep any non-settings, like commands and functions, in a dedicated ~/.emacs.d/.ercrc.el. Whatever the case, please keep in mind that you can replace nearly all of the following with Custom settings (see Sample configuration via Customize).
;;; My ERC configuration -*- lexical-binding: t -*-
(use-package erc
:config
;; Prefer SASL to NickServ, colorize nicknames, and show side panels
;; with joined channels and members
(setopt erc-modules
(seq-union '(sasl nicks bufbar nickbar scrolltobottom)
erc-modules))
:custom
;; Protect me from accidentally sending excess lines.
(erc-inhibit-multiline-input t)
(erc-send-whitespace-lines t)
(erc-ask-about-multiline-input t)
;; Scroll all windows to prompt when submitting input.
(erc-scrolltobottom-all t)
;; Reconnect automatically using a fancy strategy.
(erc-server-reconnect-function #'erc-server-delayed-check-reconnect)
(erc-server-reconnect-timeout 30)
;; Show new buffers in the current window instead of a split.
(erc-interactive-display 'buffer)
;; Insert a newline when I hit <RET> at the prompt, and prefer
;; something more deliberate for actually sending messages.
:bind (:map erc-mode-map
("RET" . nil)
("C-c C-c" . #'erc-send-current-line))
;; Emphasize buttonized text in notices.
:custom-face (erc-notice-face ((t (:slant italic :weight unspecified)))))
(use-package erc-sasl
;; Since my account name is the same as my nick, free me from having
;; to hit C-u before M-x erc to trigger a username prompt.
:custom (erc-sasl-user :nick))
(use-package erc-join
;; Join #emacs and #erc whenever I connect to Libera.Chat.
:custom (erc-autojoin-channels-alist '((Libera.Chat "#emacs" "#erc"))))
(use-package erc-fill
:custom
;; Prefer one message per line without continuation indicators.
(erc-fill-function #'erc-fill-wrap)
(erc-fill-static-center 18)
:bind (:map erc-fill-wrap-mode-map ("C-c =" . #'erc-fill-wrap-nudge)))
(use-package erc-match
;; Use the same face for my own nick wherever it appears.
:custom-face
(erc-current-nick-face ((t ( :weight unspecified
:foreground unspecified
:inherit erc-my-nick-face)))))
(use-package erc-track
;; Prevent JOINs and PARTs from lighting up the mode-line.
:config (setopt erc-track-faces-priority-list
(remq 'erc-notice-face erc-track-faces-priority-list))
:custom (erc-track-priority-faces-only 'all))
(use-package erc-goodies
;; Turn on read indicators when joining channels.
:hook (erc-join . my-erc-enable-keep-place-indicator-on-join))
(defvar my-erc-read-indicator-channels '("#emacs")
"Channels in which to show a `keep-place-indicator'.")
(defun my-erc-enable-keep-place-indicator-on-join ()
"Enable read indicators for certain queries or channels."
(when (member (erc-default-target) my-erc-read-indicator-channels)
(erc-keep-place-indicator-mode +1)))
;; Handy commands from the Emacs Wiki.
(defun erc-cmd-TRACK (&optional target)
"Start tracking TARGET or that of current buffer."
(setq erc-track-exclude
(delete (or target (erc-default-target) (current-buffer))
erc-track-exclude)))
(defun erc-cmd-UNTRACK (&optional target)
"Stop tracking TARGET or that of current buffer."
(setq erc-track-exclude
(cl-pushnew (or target (erc-default-target) (current-buffer))
erc-track-exclude
:test #'equal)))
Those familiar with use-package may have noticed the lack of
:defer keyword args. This was done to conserve space, but you
can just pretend that this user has enabled
use-package-always-defer elsewhere.
As mentioned, Customize users can accomplish nearly all of the above via the Customize interface. Start by running M-x customize-group RET erc RET, and search for “Modules” with C-s modules RET. Toggle open the flyout menu to reveal the full widget panel, a web-form-like interface for “Erc Modules”. Tick the boxes for ‘bufbar’, ‘nickbar’, ‘nicks’, ‘sasl’, and ‘scrolltobottom’.
Next, search for the phrases “Erc Ask About Multiline Input”, “Erc
Inhibit Multiline Input”, and “Erc Send Whitespace Lines”. These
are the print names of three boolean options that control how ERC
treats prompt input containing line breaks. When visiting each
option’s section, twirl open its triangle icon to reveal its widget
UI, and click its ‘[Toggle]’ button to set its value to t.
While going about this, you may find it helpful to glance at the
descriptions just in case you want to disable them later. When
finished, hit C-x C-s or click ‘[Apply and Save]’ atop the
buffer.
Now do the same for another couple options, this time having to do with automatic reconnection. But instead of searching for their print names, try running M-x customize-option RET ‘<option>’ RET, replacing ‘<option>’ with:
erc-server-reconnect-function, a function
erc-server-reconnect-timeout, a number
(If it helps, hit TAB for completion.) As you may have noticed,
when customizing options individually, each buffer displays but a
single option’s widget. When you get to the buffer for “Erc Server
Reconnect Function”, you’ll see that ‘[Toggle]’ has been
replaced with ‘[Value Menu]’ and that clicking it reveals three
choices in a pop-up window. Enter 1 to select
erc-server-delayed-check-reconnect before TAB’ing over to
‘[State]’ and hitting RET. Enter 1 again, this time
to persists your changes.
For the final option, erc-server-reconnect-timeout, you’ll
encounter a text field (instead of a button), which works like those
in a typical web form. Enter ‘30’ and hit C-x C-s to save.
Just for fun, click the group link for ‘Erc Server’ at the bottom
of the buffer. You could just as well have set the last two options
from this “custom group” buffer alone, which very much resembles the
one for the ‘Erc’ group, which is actually the “parent” of this
group (note the “breadcrumb” for group ‘Erc’ atop the buffer).
Indeed, you can always get back here by running M-x
customize-group RET erc-server RET from almost anywhere
in Emacs.
To make sure you’ve got this, try quickly customizing the option
erc-interactive-display, which lives in the ‘Erc Buffers’
group (M-x customize-group RET erc-buffers RET). As
its doc string explains, the option controls where new buffers show up
when you do M-x erc-tls RET or issue certain slash
commands, like /JOIN #emacs-beginners RET, at ERC’s
prompt. Change its value to the symbol buffer by choosing
‘Use current window’ (item 5) from the option’s
‘[Value Menu]’. Don’t forget to save.
If you need more practice, try enabling the boolean option
erc-scrolltobottom-all, which lives in the ‘Erc Display’
group (M-x customize-group RET erc-display RET).
When enabled, this option tells the ‘scrolltobottom’ module to
adjust all ERC windows instead of just the one you’re currently typing
in.
Now it’s time to set some key bindings for erc-mode-map, a
major-mode keymap active in all ERC buffers. In general, it’s best to
do this part either entirely or in conjunction with some lisp code in
you init file. However, to keep things “simple”, we’ll do it all in
customization buffers. To get started, hit M-x customize-group
RET erc-hooks RET and search for “Erc Mode Hook”. In
the widget form, click ‘[INS]’, and paste the following into the
value field in place of the default text.
(lambda () (keymap-set erc-mode-map "RET" nil) (keymap-set erc-mode-map "C-c C-c" 'erc-send-current-line))
Don’t worry about the line breaks. Emacs is smart enough to handle those. When you’re ready, click ‘[Apply and Save]’.
Next, try tweaking the face ERC uses to stylize server messages that say things like “SoAndSo has joined channel #chan”. Type M-x customize-face RET erc-notice-face RET. Click the “link”-looking button at the very bottom that says something like “Show All Attributes”. Untick ‘Weight’ and tick ‘Slant’. Then, in the latter’s ‘[Value Menu]’, enter ‘0’ for ‘italic’. Hit C-x C-s to save.
Time for some more involved configuring. From now on, if something
isn’t applicable to your setup, just skip ahead. Also, note that if
you’ve installed ERC from GNU ELPA, you may need to load libraries for
groups and options you’d like to customize before Emacs can create a
customization buffer. For example, to do this for the group
erc-sasl, run M-: (require 'erc-sasl) RET.
Speaking of SASL, those already authenticating with it may
have noticed that connecting interactively requires running C-u
M-x erc-tls RET in order to receive a “User” prompt for your
account name. However, if your nickname happens to be the same as
your account name, you can avoid the leading C-u by customizing
the option erc-sasl-user to the keyword symbol :nick.
At the time of writing, you’d hit 2 when prompted by the
option’s ‘[Value menu]’. Hit C-x C-s to save your changes.
One of ERC’s most configured options lives in erc-join, and it
determines the channels you join upon connecting. To make it work for
you, customize the option erc-autojoin-channels-alist. In the
customization widget, hit ‘[INS]’ to create a new entry. In the
‘Network:’ field, type ‘Libera.Chat’. Under
‘Channels:’, hit ‘[INS]’ again, this time to create a field
to enter a channel name, and enter ‘#emacs’. Now, find and click
on the lowermost ‘[INS]’, and this time enter ‘#erc’ in the
‘Name:’ field. Save your changes.
If you’re new to ERC, you may not be familiar with the various ways it
can “fill” message text by inserting line breaks. The most modern
fill style is called fill-wrap, and it’s available by
customizing erc-fill-function to erc-fill-wrap, which
appears as ‘Dynamic word-wrap’ in the option’s ‘[Value
Menu]’. After setting this, change the related option
erc-fill-static-center to the integer ‘18’. Save your
changes. As a bonus exercise, try binding the key C-c = to the
function erc-fill-wrap-nudge in the minor-mode keymap
erc-fill-wrap-mode-map (hint: the minor mode’s hook is called
erc-fill-wrap-mode-hook, and it’s not a member of any
customization group).
Try customizing another face, this time with inheritance. ERC’s match
module highlights your nick whenever someone mentions you in
conversation. However, some users don’t like that this face differs
from the one in your own messages. Let’s change that. Type M-x
customize-group RET erc-faces RET. Either search for the
word “Current” or type M-x customize-face RET
erc-current-nick-face RET. Untick ‘Weight’ and
‘Foreground’, then click the “Show All Attributes” button below
them. Navigate down to the ‘Inherit’ box, tick it, hit
‘[INS]’, and type erc-my-nick-face in the ‘Face’ field.
Hit C-x C-s to save.
ERC users tend to be picky about the mode line. If you find that
you’d rather not see changes when people join and leave channels,
customize the option erc-track-faces-priority-list. When
visiting its customization buffer, you’ll notice it’s quite busy.
Ignore everything and type C-s erc-notice-face RET. Click
the ‘[DEL]’ button at the beginning of the line you end up on,
and save your changes. Next, customize the related option
erc-track-priority-faces-only to the ‘[Value Menu]’ choice
‘all’. Once again, save your changes.
Let’s say you’d like to enable a local module (ERC’s version of
a local minor mode) in a specific channel. One way to do that is by
running some code to activate the module if the channel’s name
matches. Try that now by customizing the option erc-join-hook.
Add the following in the value field before saving your changes:
(lambda ()
(require 'erc-goodies)
(when (equal (erc-default-target) "#emacs")
(erc-keep-place-indicator-mode +1)))
Lastly, if you really want the two slash commands defined at the
end of the previous section, you can put them in any file listed in
erc-startup-file-list, such as ~/.emacs.d/.ercrc.el.
Make sure to put (require 'erc-track) near the top of the file.
These will allow you to type /TRACK RET and /UNTRACK
RET in channels and query buffers to tell ERC whether to show
activity from these buffers in the mode line.
Next: Options, Previous: Sample Configuration, Up: Advanced Usage [Contents][Index]
For anything to work, you’ll want to set url-irc-function to
url-irc-erc. As a rule of thumb, libraries relying directly on
url-retrieve should be fine out the box from Emacs 29.1 onward.
On older versions of Emacs, you may need to (require 'erc)
beforehand. See Retrieving URLs in URL.
For other apps and libraries, such as those relying on the
higher-level browse-url, you’ll oftentimes be asked to specify
a pattern, sometimes paired with a function that accepts a string URL
as a first argument. For example, with EWW, you may need to tack
something like "\\|\\`irc6?s?:" onto the end of
eww-use-browse-url. But with gnus-button-alist, you’ll
need a function as well:
'("\\birc6?s?://[][a-z0-9.,@_:+%?&/#-]+" 0 t browse-url-irc 0)
Users on Emacs 28 and below may need to use browse-url instead.
People wanting to connect to IRC through a SOCKS proxy are most likely interested in doing so over TOR (The Onion Router). If that’s not you, please adapt these instructions accordingly. Otherwise, keep in mind that support for Tor is experimental and thus insufficient for safeguarding a user’s identity and location, especially in the case of targeted individuals.
ERC’s preferred Tor setup works by accessing a local Tor service
through the built-in socks.el library that ships with Emacs.
Other means of accessing Tor, such as via torsocks, are not
supported. Before getting started, check that your Tor service is up
and running. You can do that with the following command:
curl --proxy socks5h://localhost:9050 https://check.torproject.org | \ grep 'Congratulations'
Networks and servers differ in how they expose Tor endpoints. In all
cases, you’ll want to first set the option socks-server to
something appropriate, like ("tor" "127.0.0.1" 9050 5). For
some networks, setting erc-server-connect-function to
socks-open-network-stream might be enough. Others, like
‘Libera.Chat’, involve additional setup. At the time of writing,
connecting to that network requires both TLS and a permitted
SASL mechanism, like ‘EXTERNAL’ (see Authenticating via SASL), as
shown in the following example:
(require 'erc)
(require 'socks)
(defun my-erc-open-socks-tls-stream (&rest args)
(let ((socks-username "")
(socks-password "")
(socks-server '("tor" "localhost" 9050 5)))
(apply #'erc-open-socks-tls-stream args)))
(let* ((erc-modules (cons 'sasl erc-modules))
(erc-sasl-mechanism 'external)
(erc-server-connect-function #'my-erc-open-socks-tls-stream))
(erc-tls
:server "libera75jm6of4wxpxt4aynol3xjmbtxgfyjpu34ss4d7r7q2v5zrpyd.onion"
:port 6697
:nick "jrh"
:user "jrandomhacker"
:full-name "J. Random Hacker"
:client-certificate (list "/home/jrh/key.pem" "/home/jrh/cert.pem")))
Here, the user-provided my-erc-open-socks-tls-stream ensures
that the preferred values for socks-server and friends will be
available when reconnecting. If you plan on using SOCKS
with ERC exclusively, you can just set those options and variables
globally and bind erc-server-connect-function to
erc-open-socks-tls-stream instead.
Next: display-buffer, Up: Integrations [Contents][Index]
You can configure ERC to use the built-in auth-source library for
looking up passwords. See auth-source in Emacs auth-source
Library, for general info on setting up various backends, but keep in
mind that some of these may not be compatible. Those currently
supported are netrc, plstore, json, secrets, and pass. To get started
with the default backend, netrc, put a line like the following in your
~/.authinfo.gpg (or any file named in the option
auth-sources):
machine irc.example.net login mynick password sEcReT
When retrieving passwords to accompany the IRC ‘PASS’ command
(see password parameter), ERC asks auth-source to match the
server parameter of erc-tls against each entry’s
‘host’ field (machine irc.example.net in the above
example). Unfortunately, specifying a network, like
‘Libera.Chat’, or a specific network server, like
‘platinum.libera.chat’, won’t normally work for looking up a
server password because that information isn’t available during
opening introductions. (Actually, ERC can find entries with
arbitrary ‘host’ values for any context, including server
passwords, but that requires customizing the more advanced options
below.)
If ERC can’t find a suitable server password, it will just skip the
IRC ‘PASS’ command altogether, something users may want when
using CertFP or engaging NickServ via ERC’s services module.
If that appeals to you, consider customizing the option
erc-auth-source-server-function to nil to skip
server-password lookup for all servers. Note that some networks and
IRCds may accept account-services authentication via server password.
Also, some ERC modules may commandeer the erc-tls
password parameter for their own ends, which likely don’t
involve a server password.
You can use auth-source to authenticate to account services the
traditional way through a bot called ‘NickServ’. To do so, add
services to erc-modules and set the option
erc-use-auth-source-for-nickserv-password to t. After
that, expect the ‘user’ parameter in relevant auth-source queries
to be your current nickname.
Most of the time, a query’s precise contextual details (such as
whether a nick was granted or forcibly assigned) shouldn’t affect how
you define entries in your backend. However, if something isn’t quite
working, you may want to investigate the interplay between the option
erc-nickserv-identify-mode and account services. In
particular, if you find yourself facing nicks suffixed with an
erc-nick-uniquifier (the infamous ‘`’), check that the
network’s entry in erc-nickserv-alist is up to date, and do let
us know if something’s off (see Getting Help and Reporting Bugs).
Of course, if you’ve had your fill of fiddling with this module,
consider switching to SASL for what’s likely a more consistent
auth-source experience. (See Authenticating via SASL.)
When preparing entries for your backend, it may help to get a feel for how ERC and its modules conduct searches, especially when exploring a new context, such as channel keys. Overall, though, ERC tries to be consistent in performing queries across various authentication contexts. Here’s what to expect with respect to the ‘host’ field, which, by default, most heavily influences the fate of a query:
erc-tls)
The following netrc-style entries appear in order of precedence:
machine Libera/cellphone login MyNick password sEcReT machine Libera.Chat login MyNick password sEcReT machine zirconium.libera.chat login MyNick password sEcReT machine irc.libera.chat login MyNick password sEcReT
Remember that field labels vary per backend, so ‘machine’ (in
netrc’s case) maps to auth-source’s generalized notion of a host,
hence the ‘:host’ keyword parameter to auth-source-search.
Also, be sure to mind the syntax of your chosen backend medium. For
example, always quote channel names in a netrc file.
Lastly, if this all seems overly nuanced or just plain doesn’t appeal
to you, please see options erc-auth-source-services-function
and friends, described just below.
These let you query auth-source your way. Most users can simply ignore the passed-in arguments and get by with something like the following:
(defun my-fancy-auth-source-func (&rest _)
(let* ((host (read-string "host: " nil nil "default"))
(pass (auth-source-pick-first-password :host host)))
(if (and pass (string-search "libera" host))
(concat "MyNick:" pass)
pass)))
ERC calls these functions with keyword arguments recognized by
auth-source-search, namely, those deemed most relevant to the
current context, if any. For example, when identifying to services,
:user contains your current nickname. Generalized parameter
names, like :user and :host, are always preferred over
backend specific ones, like :login or :machine. In
return, ERC expects a string if the search succeeds or nil if
it fails.
The default value for all three options is the function
erc-auth-source-search. It tries to merge relevant contextual
parameters with those provided or discovered from the logical
connection or the underlying transport.
For using auth-source along with SASL, see SASL auth-source function.
ERC also consults auth-source to find “keys” that may be
required by certain channels you join. When modifying a traditional
auth-source entry for this purpose, put the channel name in the
‘user’ field (for example, ‘login "#fsf"’, in netrc’s case).
The actual key goes in the ‘password’ (or ‘secret’) field.
By default, ERC queries auth-source for channel keys and server
passwords (see auth-source Server Password), as well as other,
module-specific credentials. In general, if you’re having trouble
calling auth-source-search in a custom query function, like
erc-auth-source-server-function, try temporarily setting the
variable auth-source-debug to t and checking
*Messages* periodically for insights into how
auth-source is operating.
If you’re using a GPG-encrypted file and find that
customizing one of the function-valued query options doesn’t solve
your problem, explore options epg-pinentry-mode and
epg-debug in the epg Custom group (see GnuPG
Pinentry in EasyPG Assistant). Additionally, keep an eye out
for an *Error* buffer, which may contain more specific clues
about your situation. If you use the libsecrets integration
(see Secret Service API in Emacs auth-source) with something
like GNOME Keyring, you may need to check the “remember” box in the
passphrase popup dialog to avoid being prompted for confirmation every
time you run ERC. If it doesn’t work at first, try logging out. And
when in doubt, try using the Emacs command secrets-show-secrets
to browse the ‘Login’ keyring. There should be a
‘GnuPG/stored-by’ entry with a value of ‘GnuPG Pinentry’ or
similar.
Previous: auth-source, Up: Integrations [Contents][Index]
ERC supports the “action” interface used by display-buffer
and friends from window.el. See Displaying Buffers in Emacs Lisp, for specifics. When ERC displays a new or
“reassociated” buffer, it consults its various buffer-display
options, such as erc-buffer-display, to decide whether and how
the buffer ought to appear in a window. Exactly which one it consults
depends on the context in which the buffer is being manifested.
For some buffer-display options, the context is pretty cut and dry.
For instance, in the case of erc-receive-query-display, you’re
receiving a query from someone you haven’t yet chatted with in the
current session. For other options, like
erc-interactive-display, the precise context varies. For
example, you might be opening a query buffer with the command
/QUERY bob RET or joining a new channel with /JOIN
#chan RET. Power users wishing to distinguish between such
nuanced contexts or just exercise more control over buffer-display
behavior generally can elect to override these options by setting one
or more to a “display-buffer-like” function that accepts a
buffer and an action argument.
In this first example, a user-provided buffer-display function
displays new server buffers in the current window when issuing an
M-x erc-tls RET and in a split window for all other
interactve contexts covered by the option
erc-interactive-display, like clicking an ‘irc://’-style
URL (see URL).
(defun my-erc-interactive-display-buffer (buffer action)
"Pop to BUFFER when running \\[erc-tls], clicking a link, etc."
(when-let* ((alist (cdr action))
(found (alist-get 'erc-interactive-display alist)))
(if (eq found 'erc-tls)
(pop-to-buffer-same-window buffer action)
(pop-to-buffer buffer action))))
(setopt erc-interactive-display #'my-erc-interactive-display-buffer)
Observe that ERC supplies the names of buffer-display options as action alist keys and pairs them with contextual constants, like the symbols ‘erc-tls’ or ‘url’, the full lineup of which are listed below.
In this second example, for Emacs 29 and above, the user writes three
predicates that somewhat resemble the “display-buffer-like”
function above. These too look for action alist keys sharing
the names of ERC’s buffer-display options (and, in one case, a
module’s minor mode).
(defun my-erc-disp-entry-p (_ action)
(memq (cdr (or (assq 'erc-buffer-display action)
(assq 'erc-interactive-display action)))
'(erc-tls url)))
(defun my-erc-disp-query-p (_ action)
(or (eq (cdr (assq 'erc-interactive-display action)) '/QUERY)
(and (eq (cdr (assq 'erc-receive-query-display action)) 'PRIVMSG)
(member (erc-default-target) '("bob" "alice")))))
(defun my-erc-disp-chan-p (_ action)
(or (assq 'erc-autojoin-mode action)
(and (eq (cdr (assq 'erc-buffer-display action)) 'JOIN)
(member (erc-default-target) '("#emacs" "#fsf")))))
You’ll notice we ignore the buffer parameter of these predicates
because ERC ensures that buffer is already current (which is why
we can freely call erc-default-target). Note also that we
cheat a little by treating the action parameter like an alist
when it’s really a cons of one or more functions and an alist.
To complement our predicates, we set all three buffer-display options
referenced in their action-alist lookups to
display-buffer. This tells ERC to defer to that function in
the display contexts covered by these options.
(setopt erc-buffer-display #'display-buffer
erc-interactive-display #'display-buffer
erc-receive-query-display #'display-buffer
;;
erc-auto-reconnect-display 'bury)
The last option above just tells ERC to avoid any buffer-display
machinery when auto-reconnecting. (For historical reasons, ERC’s
buffer-display options use the term “bury” to mean “ignore” rather
than bury-buffer.)
Finally, we compose our predicates into buffer-match-p
conditions and pair them with various well known display-buffer
action functions and action-alist members.
(setopt display-buffer-alist
;; Create new frame with M-x erc-tls RET or (erc-tls ...)
'(((and (major-mode . erc-mode) my-erc-disp-entry-p)
display-buffer-pop-up-frame
(reusable-frames . visible))
;; Show important chans and queries in a split.
((and (major-mode . erc-mode)
(or my-erc-disp-chan-p my-erc-disp-query-p))
display-buffer-pop-up-window)
;; Ignore everything else.
((major-mode . erc-mode)
display-buffer-no-window
(allow-no-window . t))))
Of course, we could just as well set our buffer-display options to one
or more homespun functions instead of bothering with
display-buffer-alist at all (in what would make for a more
complicated version of our first example). But perhaps we already
have a growing menagerie of similar predicates and like to keep
everything in one place in our init.el.
All keys are symbols, as are values, unless otherwise noted.
erc-buffer-display
erc-interactive-display
erc-receive-query-display
erc-auto-reconnect-display
nil
erc-autojoin-mode
"#chan"
Previous: Integrations, Up: Advanced Usage [Contents][Index]
This section is extremely incomplete. For now, the easiest way to check out all the available options for ERC is to do M-x customize-group RET erc RET.
If non, nil, this is a list of IRC message types to hide, e.g.:
(setq erc-hide-list '("JOIN" "PART" "QUIT"))
If non, nil, this is a list of IRC networks and message types
to hide, e.g.:
(setq erc-network-hide-list (("Libera.Chat" "JOIN" "PART" "QUIT")
("OFTC" "JOIN" "PART""))
If non, nil, this is a list of IRC channels and message types
to hide, e.g.:
(setq erc-channel-hide-list (("#erc" "JOIN" "PART" "QUIT")
("#emacs" "NICK"))
Like erc-hide-list, but only applies to messages sent by
lurkers. The function erc-lurker-p determines whether a given
nickname is considered a lurker.
Next: History, Previous: Advanced Usage, Up: ERC [Contents][Index]
After you have read this guide, if you still have questions about ERC, or if you have bugs to report, there are several places you can go.
To upgrade, run M-x list-packages RET. In the
*Packages* (package-menu-mode) buffer, click the
‘erc’ package link for the desired version. If unsure, or if the
version column is too narrow to tell, try the bottom-most candidate.
In the resulting help-mode buffer, confirm the version and
click ‘Install’. Make sure to restart Emacs before reconnecting
to IRC, and don’t forget that you can roll back to the previous
version by running M-x package-delete RET.
See Packages in The Emacs Editor, for more information.
Note that a bug affecting Emacs’s packaging machinery may prevent the
above method from working on Emacs versions 29 and below. Users on 29
can try running C-u M-x package-install RET instead.
Users on 28 and below can click on the installed ‘erc’
line item in the *Packages* buffer instead of the newest one,
and then, in the resulting help-mode buffer, find and activate
the button for the newest version, which should appear in the summary
item ‘Other versions’.
In the rare instance you need an emergency fix or have volunteered to
test an edge feature between ERC releases, you can try adding
‘("devel" . "https://elpa.gnu.org/devel/")’ to
package-archives prior to performing the steps above. For
this, you’ll want to instead select a snapshot version from the
menu. Please be aware that when going this route, the latest changes
may not yet be available and you run the risk of incurring other bugs
and encountering unstable features.
Next: GNU Free Documentation License, Previous: Getting Help and Reporting Bugs, Up: ERC [Contents][Index]
ERC was originally written by Alexander L. Belikoff and Sergey Berezin. They stopped development around December 1999. Their last released version was ERC 2.0.
P.S.: If one of the original developers of ERC reads this, we’d like to receive additional information for this file and hear comments in general.
In June 2001, Mario Lang and Alex Schroeder took over development and created a ERC Project at https://sourceforge.net/projects/erc.
In reaction to a mail about the new ERC development effort, Sergey Berezin said, “First of all, I’m glad that my version of ERC is being used out there. The thing is, I do not have free time and enough incentive anymore to work on ERC, so I would be happy if you guys take over the project entirely.”
So we happily hacked away on ERC, and soon after (September 2001) released the next "stable" version, 2.1.
Most of the development of the new ERC happened on ‘#emacs’ on irc.openprojects.net. Over time, many people contributed code, ideas, bugfixes, and a lot of alpha/beta/gamma testing.
See the CREDITS file for a list of contributors.
ERC 3.0 was released.
ERC 4.0 was released.
ERC 5.0 was released. Michael Olson became the release manager and eventually the maintainer.
After some discussion between him and the Emacs developers, it was decided to include ERC in Emacs.
ERC 5.1 was released. It was subsequently included in Emacs 22.
ERC became an official GNU project, and development moved to https://sv.gnu.org/projects/erc. We switched to using GNU Arch as our revision control system. Our mailing list address changed as well.
We switched to using git for our version control system.
Since about 2009, ERC is no longer developed as a separate project, but is maintained as part of Emacs.
The official channels for GNU Emacs and ERC lived on the Freenode IRC network until June 2021, when they—along with the official IRC channels of the GNU Project, the Free Software Foundation, and many other free software communities—relocated to the Libera.Chat network in the aftermath of changes in governance and policies of Freenode in May and June 2021. GNU and FSF’s announcements about this are at https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00005.html, https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00007.html, and https://lists.gnu.org/archive/html/info-gnu-emacs/2021-06/msg00000.html.
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