Debianization and various other fixes.

[ezmlm] / ezmlm-archive.1

.TH ezmlm-archive 1
.SH NAME
ezmlm-archive \- create thread and author index for a mailing list archive
.SH SYNOPSIS
.B ezmlm-archive
[
.B \-cCFTvV
][
.B \-f\fI msg1
]
][
.B \-t\fI msg2
]
.I dir
.SH DESCRIPTION
.B ezmlm-archive
reads the index files from a message archive, and creates a subject index, a
collection of subject files, and a collection of author files. These
files are suitable as an index for WWW access to, and navigation through
a mailing list archive by
.BR ezmlm-cgi(1) .

The index files read are created by
.B ezmlm-idx(1)
on a per-list basis and by
.B ezmlm-send(1)
on a per-message archive for a indexed list.

The output files created are:
.TP
.I dir\fB/archive/threads/yyyymm
The thread index. It contains one line per subject, starting with the
number of the first message with that subject within the set
investigated, ``:'', a 20 character
subject hash, blank, ``[n]'' where ``n'' is the number of messages in the
thread, blank, and the subject.
The file ``yyyymm'' contains
entries for all threads that have messages in the month ``yyyymm''
or that have messages both before and after that month.
The subject hash is a key to the subject files; the message number is
a key to the index file.
The lines are in ascending order by message number when the index is
created
.I de novo
on an existing archive. When the messages are added one-by-one as in normal
archive operation, ``n'' is the number of message in the thread
.I for the particular month
and the order is in reverse of latest message, i.e. the last extended thread
is shown last. The message number accompanying a thread is
always a message within the thread. It is the first in
archives created
on existing lists, and the last message in incrementally created archives.
Use the corresponding subject index file to get a list of all
messages in the thread in ascending order.
.TP
.I dir\fB/archive/subjects/xx/yyyyyyyyyyyyyyyyyy
A subject file. The first line is the subject hash, a space, and the subject.
This is followed by one line per message with this subject, in the format
message number, ``:'', date (yyyymm), ``:'',
author hash, blank, author from line. The lines are
sorted by message number. The author hash is a key to the author files;
the message number is a key to the index file. The file in the example
would be for the subject hash ``xxyyyyyyyyyyyyyyyyyy''.
.TP
.I dir\fB/archive/authors/xx/yyyyyyyyyyyyyyyyyy
An author file. The first line is the author hash, a space, and the author
from line.
This is followed by one line per message with this author, in the format
message number, ``:'', date (yyyymm), ``:'',
subject hash, blank, subject. The lines are
sorted by message number. The subject hash is a key to the subject files;
the message number is a key to the index file. The file in the example
would be for the author hash ``xxyyyyyyyyyyyyyyyyyy''.

.I dir\fB/archnum
keeps track of the last message processed. Normally,
.B ezmlm-archive
will process entries for messages from one above the contents of this file
up to an including the message number in
.IR dir\fB/num .
.SH OPTIONS
.B ezmlm-archive
writes messages in a crash-proof manner when run in normal mode. When overriding
the normal message range with any of the options listed, the normal
.B sync(3)
of the output files is suppressed for efficiency. Should the computer crash
during this time the state of the indices is not defined. Use the
.B \-s
option in the (extremely rare) cases where this would be a problem.
.TP
.B \-c
Create a new index. This  overrides
.I dir\fB/archnum
causing
.B ezmlm-archive
to start with the first message in the archive. Synonym for
.BR \-f\fI0 .
.B NOTE:
.B ezmlm-archive
does not remove files in the index. While it will overwrite/update old files
it will not remove files that are obsolete for other reasons.
.TP
.B \-C
(Default.)
Process entries starting with the message after the message listed in
.IR dir\fB/archnum .
.TP
.B \-f\fI msg1
Process messages from the archive section (set of 100 messages)
containing message
.IR msg1 .
This is useful if you have removed part of the archive, as it will shorten
processing time and decrease memory use.
.B NOTE:
.B ezmlm-archive
does not remove files in the index. While it will overwrite/update old files
it will not remove files that are obsolete for other reasons. The number of
messages per thread will be incorrect when using of the
.B \-f
and
.B \-t
switches leads to partial re-indexing of already indexed messages.
.TP
.B \-F
(Default.)
Do not change the starting message from the default
(see
.BR \-C ).
.TP
.B \-s
Always sync files.
.TP
.B \-S
(Default.)
Sync files, except when on of the message range modifying options is
used.
.TP
.B \-t\fI msg2
Process messages to message
.I msg2
instead of the last message in the archive. Again, files written are
corrected, but other files are not explicitly removed.
.TP
.B \-T
(Default.)
Process entries for messages up to the last message in the archive.
.TP
.B \-v
Display
.B ezmlm-archive
version info.
.TP
.B \-V
Display
.B ezmlm-archive
version info.
.SH "MEMORY USAGE"
.B ezmlm-archive
stores its linked lists in memory. On at 32-bit architecture, it uses
12 bytes per message, 28 bytes per thread (plus one copy of the subject),
and 20 bytes per author (plus one copy of the author from line).

In normal list use, it processes only at most a few messages at a time,
but for initial processing of a large archive, considerable amounts of
memory may be used. Assuming
40 bytes for subject/from line, 5 messages per thread, 100,000 messages,
and 1000 authors, this is 2.5 MB. For 1,000,000 messages this is about 20 MB.

Thus, for large archives, it may be useful to use the
.I \-t
switch to process the archive in multiple subsets, starting with e.g. the first
100,000, then the next, and so on.
.SH "SEE ALSO"
ezmlm-cgi(1),
ezmlm-idx(1),
ezmlm-send(1),
ezmlm(5)