notmuch-dump man page
notmuch-dump — creates a plain-text dump of the tags of each message
notmuch dump [--gzip] [--format=(batch-tag|sup)] [--output=<file>] [--] [<search-term> ...]
Dump tags for messages matching the given search terms.
Output is to the given filename, if any, or to stdout.
These tags are the only data in the notmuch database that can't be recreated from the messages themselves. The output of notmuch dump is therefore the only critical thing to backup (and much more friendly to incremental backup than the native database files.)
See notmuch-search-terms(7) for details of the supported syntax for <search-terms>. With no search terms, a dump of all messages in the database will be generated. A "--" argument instructs notmuch that the remaining arguments are search terms.
Supported options for dump include
Compress the output in a format compatible with gzip(1).
Notmuch restore supports two plain text dump formats, both with one message-id per line, followed by a list of tags.
The default batch-tag dump format is intended to more robust against malformed message-ids and tags containing whitespace or non-ascii(7) characters. Each line has the form
+<encoded-tag> +<encoded-tag> ... -- id:<quoted-message-id>
Tags are hex-encoded by replacing every byte not matching the regex [A-Za-z0-9@=.,_+-] with %nn where nn is the two digit hex encoding. The message ID is a valid Xapian query, quoted using Xapian boolean term quoting rules: if the ID contains whitespace or a close paren or starts with a double quote, it must be enclosed in double quotes and double quotes inside the ID must be doubled. The astute reader will notice this is a special case of the batch input format for notmuch-tag(1); note that the single message-id query is mandatory for notmuch-restore(1).
The sup dump file format is specifically chosen to be compatible with the format of files produced by sup-dump. So if you've previously been using sup for mail, then the notmuch restore command provides you a way to import all of your tags (or labels as sup calls them). Each line has the following form
<message-id> ( <tag> ... )
with zero or more tags are separated by spaces. Note that (malformed) message-ids may contain arbitrary non-null characters. Note also that tags with spaces will not be correctly restored with this format.
Control what kind of metadata is included in the output.
Output configuration data stored in the database. Each line starts with "#@ ", followed by a space separated key-value pair. Both key and value are hex encoded if needed.
Output per-message (key,value) metadata. Each line starts with "#= ", followed by a message id, and a space separated list of key=value pairs. pair. Ids, keys and values are hex encoded if needed.
Output per-message boolean metadata, namely tags. See format above for description of the output.
The default is to include all available types of data. The option can be specified multiple times to select some subset. As of version 3 of the dump format, there is a header line of the following form
#notmuch-dump <format>:<version> <included>
where <included> is a comma separated list of the above options.
Write output to given file instead of stdout.
notmuch(1), notmuch-config(1), notmuch-count(1), notmuch-hooks(5), notmuch-insert(1), notmuch-new(1), notmuch-reply(1), notmuch-restore(1), notmuch-search(1), notmuch-search-terms(7), notmuch-show(1), notmuch-tag(1)
Carl Worth and many others
2009-2017, Carl Worth and many others
notmuch(1), notmuch-address(1), notmuch-compact(1), notmuch-config(1), notmuch-count(1), notmuch-hooks(5), notmuch-insert(1), notmuch-new(1), notmuch-reply(1), notmuch-restore(1), notmuch-search(1), notmuch-search-terms(7), notmuch-show(1), notmuch-tag(1).