dwww-cache - manage the dwww cache of converted documents
dwww-cache --lookup type location
dwww-cache --store type location
dwww-cache --list type location
manages the cache of converted documents; it is part of
(7). An option (the first argument) specifies the operation. Some
operations operate on the whole cache, and need no other arguments. Others
need the second and third argument to specify the type and pathname of the
original document. (See dwww-convert
(8) for more information about the
The operations are:
- If the document is in the cache, output it to the standard
output. Otherwise, output nothing and return a non-zero status.
- Read the document from the standard input, output it to the
standard output and store it into the cache. If there was an older version
already in the cache, remove it.
- Output information about one document in the cache to the
standard output. The information is one line, with five space delimited
fields: type, pathname of original file, pathname of cached file, size
(actually the last two bytes of size) of the cached file, and cache entry
validity indicator (which can be either "valid" or
- Like --list, but for all documents.
- Forget all cached documents that are already outdated.
maintains a database with information of the cached documents.
The documents themselves are stored in separate files in the cache directory.
When old documents are removed from the cache by a suitable crontab entry,
they will still exist in the database. The --clean
all entries from the database where either the original or the converted file
is missing or where the converted file is outdated.
To stop the cache from growing too large, there should be an entry for
(8) in system crontab
to remove cached files
that have not been accessed for a while. The dwww-refresh-cache
program internally uses commands similar to
find /var/cache/dwww -atime +$DWWW_KEEPDAYS |
xargs rm -f
to remove all documents that have not been accessed for a number of days
specified in the $DWWW_KEEPDAYS
The idea is to first delete the old cached files and then clean up the database.
The policy of cleaning the cache has been kept outside of dwww-cache
keep the program simple, and to allow maximum flexibility. The default
installation creates a /etc/cron.daily/dwww
automatically cleans the cache each day.
- The cache directory.
- The database with information about all cached documents.
This is a binary file, specially encoded for small size and high speed,
and should not be touched by anyone but dwww-cache.
Lars Wirzenius <firstname.lastname@example.org>. Modified by Robert Luberda
(7) for copyrights and stuff.