NAME¶

mu_server - the mu backend for the mu4e e-mail client

DESCRIPTION¶

mu server starts a simple shell in which can manipulate the mu database. The output of the commands is terms of Lisp symbolic expressions (s-exps). mu server is not meant for use by humans; instead, it is designed specifically for the mu4e e-mail client. In this man-page, we document the commands mu server accepts, as well as their responses. In general, the commands sent to the server are of the form

   <command> [<parameters>]*

where each of the parameters is prefixed by their name and a colon. For example, to view a certain message, the command would be:

   view docid:12345

Parameters can be sent in any order, and parameters not used by a certain command are simply ignored.

OUTPUT FORMAT¶

mu server accepts a number of commands, and delivers its results in the form:

   \376<length>\377<s-expr>

\376 (one byte 0xfe), followed by the length of the s-expression expressed as an hexadecimal number, followed by another \377 (one byte 0xff), followed by the actual s-expression. By prefixing the expression with its length, it can be processed more efficiently. The \376 and \377 were chosen since they never occur in valid UTF-8 (in which the s-expressions are encoded).

COMMAND AND RESPONSE¶

add

 

Using the add command, we can add a message to the database.

 

-> add path:<path> maildir:<maildir>
<- (:info add :path <path> :docid <docid>)
    

 

 

compose

 

Using the compose command, we get the (original) message, and tell what to do with it. The user-interface is then expected to pre-process the message, e.g. set the subject, sender and recipient for a reply message.

 

Messages of type 'new' don't use the docid: parameter, the other ones do.

 

-> compose <reply|forward|edit|new> [docid:<docid>]
<- (:compose <reply|forward|edit|new> :original <s-exp> :include (<list-of-attachments))
    

 

The <list-of-attachments> is an s-expression describing the attachments to include in the message; this currently only applies to message we are forwarding. This s-exprssion looks like:

 

   (:file-name <filename> :mime-type <mime-type> :disposition <disposition>)
    

 

 

extract

 

Using the extract command we can save and open attachments.

-> extract action:<save|open|temp> index:<index> [path:<path>] [what:<what> [param:<param>]]
    

 

If the action is 'save', the path argument is required; the attachment will be saved, and a message

<- (:info save :message "... has been saved")
    

is sent.

 

If the action is 'open', the attachment will saved to a temporary file, after which it will be opened with the default handler for this kind of file (see mu-extract(1)), and a message

<- (:info open :message "... has been opened")
    

is sent.

 

If the action is 'temp', the arguments 'what' is required. The attachment will saved to a temporary file, and the following message is sent:

<- (:temp :what <what> :param <param)
    

The front-end can then take action on the temp file, based on what :what and :param contain. mu4e uses this mechanism e.g. for piping an attachment to a shell command.

 

find

 

Using the find command we can search for messages.

-> find query:"<query>" [maxnum:<maxnum>]
    

First, this will return an 'erase'-sexp, to clear the buffer from possible results from a previous query.

<- (:erase t)
    

 

This will return a series of 0 up to <maxnum> s-expression corresponding to each message found (if there's no maxnum, all results will be returned). The information message s-exps this function returns do not contain the message body; the view command is for that.

<- (...)
    

and finally, we receive:

<- (:found <number-of-matches>)
    

 

 

index

 

Using the index command, we can (re)index the database, similar to what mu find does.

 

-> index path:<path>
    

As a response, it will send (for each 500 messages):

(:info index :status running :processed <processed> :updated <updated>)
    

and finally:

(:info index :status complete :processed <processed :updated <updated>
 :cleaned-up <cleaned-up>)
    

 

mkdir

 

Using the mkdir command, we can create a new maildir.

 

-> mkdir path:<path>
<- (:info mkdir :message "<maildir> has been created")
    

 

move

 

Using the move command, we can move messages to another maildir or change its flags (which ultimately means it is being move to a different filename), and update the database correspondingly. The function returns an s-exp describing the updated message, so that it can be updated in the user interface.

 

-> move docid:<docid>|msgid:<msgid> [maildir:<maildir>] [flags:<flags>]
<- (:update <s-exp> :move t)
    

 

One of docid and msgid must be specified to identify the message. At least one of maildir and flags must be specified.

 

 

ping

 

The ping command provokes a pong response. It is used for the initial handshake between mu4e and mu server.

-> ping
<- (:pong "mu" :version <version> :doccount <doccount>)
    

 

remove

 

Using the remove command, we can remove the message from disk, and update the database accordingly.

 

-> remove docid:<docid>
<- (:remove <docid>)
    

 

 

view

 

Using the view command, we can all information (including the body) of a particular e-mail message.

 

-> view docid:<docid>|msgid:<msgid>
<- (:view <s-exp>)
    

 

 

AUTHOR¶

Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>

SEE ALSO¶

mu(1)