Man1 - mu-index.1

mu index - index e-mail messages stored in Maildirs

mu index [options]

mu index is the mu command for scanning the contents of Maildir directories and storing the results in a Xapian database. The data can then be queried using *mu-find*(1).

Note that before the first time you run mu index, you must run mu init to initialize the database.

index understands Maildirs as defined by Daniel Bernstein for *qmail*(7). In addition, it understands recursive Maildirs (Maildirs within Maildirs), Maildir++. It can also deal with VFAT-based Maildirs which use ’!’ or ’;’ as the separators instead of ’:’.

E-mail messages which are not stored in something resembling a maildir leaf-directory (cur and new) are ignored, as are the cache directories for notmuch and gnus, and any dot-directory.

Starting with mu 1.5.x, symlinks are followed, and can be spread over multiple filesystems; however note that moving files around is much faster when multiple filesystems are not involved.

If there is a file called .noindex in a directory, the contents of that directory and all of its subdirectories will be ignored. This can be useful to exclude certain directories from the indexing process, for example directories with spam-messages.

If there is a file called .noupdate in a directory, the contents of that directory and all of its subdirectories will be ignored, unless we do a full rebuild (with mu init). This can be useful to speed up things you have some maildirs that never change. Note that you can still search for these messages, this only affects updating the database.

There also the –lazy-check which can greatly speed up indexing; see below for details.

The first run of mu index may take a few minutes if you have a lot of mail (tens of thousands of messages). Fortunately, such a full scan needs to be done only once; after that it suffices to index the changes, which goes much faster. See the ’Note on performance (i,ii,iii)’ below for more information.

The optional ’phase two’ of the indexing-process is the removal of messages from the database for which there is no longer a corresponding file in the Maildir. If you do not want this, you can use -n, –nocleanup.

When mu index catches one of the signals SIGINT, SIGHUP or SIGTERM (e.g., when you press Ctrl-C during the indexing process), it tries to shutdown gracefully; it tries to save and commit data, and close the database etc. If it receives another signal (e.g., when pressing Ctrl-C once more), mu index will terminate immediately.

Note, some of the general options are described in the mu(1) man-page and not here, as they apply to multiple mu commands.

–lazy-check

in lazy-check mode, mu does not consider messages for which the time-stamp (ctime) of the directory they reside in has not changed since the previous indexing run. This is much faster than the non-lazy check, but won’t update messages that have change (rather than having been added or removed), since merely editing a message does not update the directory time-stamp. Of course, you can run mu-index occasionally without –lazy-check, to pick up such messages.

–nocleanup

disables the database cleanup that mu does by default after indexing.

mu stores logs of its operations and queries in <muhome>/mu.log (by default, this is ~.cache/mu/mu.log/). Upon startup, mu checks the size of this log file. If it exceeds 1 MB, it will be moved to ~.cache/mu/mu.log.old/, overwriting any existing file of that name, and start with an empty log file. This scheme allows for continued use of mu without the need for any manual maintenance of log files.

mu index uses MAILDIR to find the user’s Maildir if it has not been specified explicitly with –maildir*=/<maildir>/. If *MAILDIR is not set, mu index will try ~/Maildir.

mu index return 0 upon successful completion, and any other number greater than 0 signals an error.

Please report bugs if you find them: https://github.com/djcb/mu/issues

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

*maildir*(5), *mu*(1), *mu-init*(1), *mu-find*(1), *mu-cfind*(1)