AERC-TEMPLATES(7) Miscellaneous Information Manual AERC-TEMPLATES(7)

aerc-templates - template file specification for aerc(1)

aerc uses the go text/template package for the template parsing. Refer to the go text/template documentation for the general syntax. The template syntax described below can be used for message template files and for dynamic formatting of some UI app.

Template files are composed of headers, followed by a newline, followed by the body text.

Example:

X-Clacks-Overhead: GNU Terry Pratchett
Hello,
Greetings,
Chuck

If you have a template that doesn't add any header, it must be preceded by a newline, to avoid parsing parts of the body as header text.

All headers defined in the template will have precedence over any headers that are initialized by aerc (e.g. Subject, To, From, Cc) when composing a new message, forwarding or replying.

The following data can be used in templates. Though they are not all available always.

Addresses

An array of mail.Address. That can be used to add sender or recipient names to the template.
  • {{.From}}: List of senders.
  • {{.Peer}}: List of senders or To recipients if the message is from you.
  • {{.To}}: List of To recipients. Not always Available.
  • {{.ReplyTo}}: List of ReplyTo recipients. Not always Available.
  • {{.Cc}}: List of Cc recipients. Not always Available.
  • {{.Bcc}}: List of Cc recipients. Not always Available.
  • {{.OriginalFrom}}: List of senders of the original message. Available for quoted reply and forward.

Example:

Get the name of the first sender.

{{(index .From 0).Name}}
{{index (.From | names) 0}}

Get the email address of the first sender.

{{(index .From 0).Address}}

Date and Time

The date and time information is always available and can be easily formatted.
  • {{.Date}}: Date and time information when the compose window is opened.
  • {{.OriginalDate}}: Date and time when the original message was received. Available for quoted reply and forward.

To format the date fields, dateFormat and .Local are provided. Refer to the TEMPLATE FUNCTIONS section for details.

Subject

The subject of the email (ThreadPrefix will be empty unless threading is enabled). 
{{.ThreadPrefix}}{{if .ThreadFolded}}{{printf "{%d}" .ThreadCount}}{{end}}{{.Subject}}

The subject of the email stripped of any Re: and Fwd: prefixes.

{{.SubjectBase}}
Threading
When threading is enabled, these attributes are available in the message list:

ThreadPrefix

If the message is part of a thread, this will contain arrows that represent the message tree based on In-Reply-To and References headers.

ThreadFolded

Will be true if the message has thread children which are hidden by :fold.

ThreadCount

The number of messages in the thread.

ThreadUnread

The number of unread messages in the thread.

Flags

List of message flags, not available when composing, replying nor forwarding. This is a list of strings that may be converted to a single string with join. 
{{.Flags | join ""}}

IsReplied, HasAttachment, IsFlagged, IsRecent, IsUnread, IsMarked, IsDraft

Individual boolean flags. not available when composing, replying nor forwarding. 
{{if .IsFlagged}}★{{end}}

Labels

Message labels (for example notmuch tags). Not available when composing, replying nor forwarding. This is a list of strings that may be converted to a single string with join. 
{{.Labels | join " "}}

Size

The size of the message in bytes. Not available when composing, replying nor forwarding. It can be formatted with humanReadable. 
{{.Size | humanReadable}}

Filename

The full path of the message file. Not available when composing, replying nor forwarding. For the notmuch backend, it returns a random filename if there are multiple files associated with the message.

Filenames

A list of the full paths of the files associated with the message. For maildir this is always a list with a single element. Not available when composing, replying nor forwarding.

Any header value

Any header value of the email. 
{{.Header "x-foo-bar"}}

Any header values of the original forwared or replied message:

{{.OriginalHeader "x-foo-bar"}}
Message-ID
The message-ID of the message. 
:term b4 am {{.MessageId}}

MIME Type

MIME type is available for quoted reply and forward.
•
{{.OriginalMIMEType}}: MIME type info of quoted mail part. Usually text/plain or text/html.

Original Message

When using quoted reply or forward, the original message is available in a field called OriginalText. 
{{.OriginalText}}

Account info

The current account name: 
{{.Account}}

Currently selected mailbox folder:

{{.Folder}}

Current message counts for all folders:

{{.Recent}} {{.Unread}} {{.Exists}}
{{.RUE}}

IANA role of the mailbox, converted to lowercase:

{{.Role}}

aerc implements two additional custom roles: A 'query' role is given to folders from a notmuch query-map and 'virtual' indicates a virtual node in the directory tree listing:

{{if eq .Role "query"}}{{...}}{{else}}{{...}}{{end}}

Current message counts for specific folders:

{{.Recent "inbox"}}
{{.Unread "inbox" "aerc/pending"}}
{{.Exists "archive" "spam" "foo/baz" "foo/bar"}}
{{.RUE "inbox"}}

Status line

The following data will only be available in the status line templates:

Connection state.

{{.Connected}}
{{.ConnectionInfo}}

General status information (e.g. filter, search) separated with [statusline].separator.

{{.ContentInfo}}

Combination of {{.ConnectionInfo}} and {{.StatusInfo}} separated with [statusline].separator.

{{.StatusInfo}}

General on/off information (e.g. passthrough, threading, sorting), separated with [statusline].separator.

{{.TrayInfo}}

Currently pressed key sequence that does not match any key binding and/or is incomplete.

{{.PendingKeys}}

Besides the standard functions described in go's text/template documentation, aerc provides the following additional functions:

wrap

Wrap the original text to the specified number of characters per line. 
{{wrap 72 .OriginalText}}

quote

Prepends each line with "> ". 
{{quote .OriginalText}}

trimSignature

Removes the signature froma passed in mail. Quoted signatures are kept as they are. 
{{trimSignature .OriginalText}}

join

Join the provided list of strings with a separator: 
{{.To | names | join ", "}}

split

Split a string into a string slice with a separator: 
{{.To | names | join ", " | split ", "}}

names

Extracts the names part from a mail.Address list. If there is no name available, the mbox (email address without @domain) is returned instead. 
{{.To | names | join ", "}}
{{index (.To | names) 0}}

firstnames

Extracts the first names part from a mail.Address list. If there is no name available, the short mbox (start of email address without @domain) is returned instead. 
{{.To | firstnames | join ", "}}
{{index (.To | firstnames) 0}}

initials

Extracts the initials from the names part from a mail.Address list. If there is no name available, the first letter of the email address is returned instead. 
{{.To | initials | join ", "}}
{{index (.To | initials) 0}}

emails

Extracts the addresses part from a mail.Address list. 
{{.To | emails | join ", "}}
{{index (.To | emails) 0}}

mboxes

Extracts the mbox part from a mail.Address list (i.e. smith from smith@example.com). 
{{.To | mboxes | join ", "}}
{{index (.To | mboxes) 0}}

shortmboxes

Extracts the short mbox part from a mail.Address list (i.e. smith from smith.and.wesson@example.com). 
{{.To | shortmboxes | join ", "}}
{{index (.To | shortmboxes) 0}}

persons

Formats a list of mail.Address into a list of strings containing the human readable form of RFC5322 (e.g. Firstname Lastname <email@address.tld>). 
{{.To | persons | join ", "}}
{{index (.To | persons) 0}}

.Attach

Attaches a file to the message being composed. 
{{.Attach '/usr/libexec/aerc/filters/html'}}

exec

Execute external command, provide the second argument to its stdin. 
{{exec `/usr/libexec/aerc/filters/html` .OriginalText}}

.Local

Convert the date to the local timezone as specified by the locale. 
{{.Date.Local}}

dateFormat

Format date and time according to the format passed as the second argument. The format must be specified according to go's time package format. 
{{dateFormat .Date "Mon Jan 2 15:04:05 -0700 MST 2006"}}

You can also use the .DateAutoFormat method to format the date according to *-time*format settings:

{{.DateAutoFormat .OriginalDate.Local}}

now

Return the current date as a golang time.Time object that can be formatted with dateFormat. 
{{dateFormat now "Mon Jan 2 15:04:05 -0700 MST 2006"}}

humanReadable

Return the human readable form of an integer value. 
{{humanReadable 3217653721}}

cwd

Return the current working directory with the user home dir replaced by ~. 
{{cwd}}

compactDir

Reduce a directory path into a compact form. The directory name will be split with / and each part will be reduced to the first letter in its name: INBOX/01_WORK/PROJECT will become I/W/PROJECT. 
{{compactDir .Folder}}

contains

Checks if a string contains a substring. 
{{contains "<!DOCTYPE html>" .OriginalText}}

hasPrefix

Checks if a string has a prefix. 
{{hasPrefix "Business" .Folder}}

toLower

Convert a string to lowercase. 
{{toLower "SPECIAL OFFER!"}}

toUpper

Convert a string to uppercase. 
{{toUpper "important"}}

replace

Perform a regular expression substitution on the passed string. 
{{replace `(.+) - .+ at .+..+` `$1` ((index .OriginalFrom 0).Name)}}

.Style

Apply a user-defined style (see aerc-stylesets(7)) to a string. 
{{.Style .Account "red"}}
{{.Style .ThreadPrefix "thread"}}{{.Subject}}

.StyleSwitch

Apply a user-defined style (see aerc-stylesets(7)) to a string if it matches one of the associated regular expressions. If the string does not match any of the expressions, leave it unstyled. 
{{.StyleSwitch .Subject (`^([[w-]+]s*)?[(RFC )?PATCH` "cyan")}}
{{.StyleSwitch (.From | names | join ", ") (case `Tim` "cyan") (case `Robin` "pink-blink") (default "blue")}}

.StyleMap

Apply user-defined styles (see aerc-stylesets(7)) to elements of a string list. The logic is the same than .StyleSwitch but works on a list of elements. An additional exclude option is available to remove the matching elements from the list. 
{{.StyleMap .Labels (exclude .Folder) (exclude `^spam$`) (case `^inbox$` "red") (case `^Archive/.*` "green") (default "blue") | join " "}}

version

Returns the version of aerc, which can be useful for things like X-Mailer. 
X-Mailer: aerc {{version}}

match

Check if a string matches a regular expression. This is intended for use in conditional control flow: 
{{if match .Folder `.*/Archive-[0-9]+`}}{{humanReadable .Unread}}{{end}}

switch

Do swich/case/default control flows. The switch value is compared with regular expressions. If none of the case/default arms match, an empty string is returned. 
{{switch .Folder (case `^INBOX$` "📥") (case `^Archive/.*` "🗃") (default "📁")}}

map

Transform a string list into another one. The logic is the same than switch but works on a list of elements. An additional exclude option is available to remove the matching elements from the list. 
{{map .Labels (exclude .Folder) (exclude `^spam$`) (case `^inbox$` "📥") (case `^Archive/.*` "🗃") | join " "}}

Function chaining

All of the template functions can be chained together if needed.

Example: Automatic HTML parsing for text/html mime type messages

{{if eq .OriginalMIMEType "text/html"}}
{{exec `/usr/libexec/aerc/filters/html` .OriginalText | wrap 72 | quote}}
{{else}}
{{wrap 72 .OriginalText | trimSignature | quote}}
{{end}}

aerc(1) aerc-config(5)

Originally created by Drew DeVault and maintained by Robin Jarry who is assisted by other open source contributors. For more information about aerc development, see https://sr.ht/~rjarry/aerc/.

2024-04-07