NAME¶
dwww-cache - manage the dwww cache of converted documents
SYNOPSIS¶
dwww-cache --lookup type location
dwww-cache --store type location
dwww-cache --list type location
dwww-cache --list-all
dwww-cache --clean
DESCRIPTION¶
dwww-cache manages the cache of converted documents; it is part of
dwww(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
arguments.)
The operations are:
- --lookup
- If the document is in the cache, output it to the standard output.
Otherwise, output nothing and return a non-zero status.
- --store
- 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.
- --list
- Output information about one document in the cache to the standard output.
The information is one line, with four space delimited fields: type,
pathname of original, pathname of cached, and permanent flag (y or
n).
- --list-all
- Like --list, but for all documents.
- --clean
- Forget all cached documents that have been deleted.
dwww-cache 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. This operation removes all entries from
the database where either the original or the converted file is now missing.
To stop the cache from growing too large, an entry in root's
crontab
should remove cached files that have not been accessed for a while. For
example, the following commands remove all documents that have not been
accessed for ten days:
find /var/cache/dwww -atime +10 | xargs rm -f
dwww-cache --clean
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 to
keep the program simple, and to allow maximum flexibility. The default
dwww installation creates a
/etc/cron.daily/dwww, which
automatically cleans the cache each day.
FILES¶
- /var/cache/dwww/db
- The cache directory.
- /var/cache/dwww/db/.cache_db
- 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.
SEE ALSO¶
dwww(7),
dwww-convert(8).
AUTHOR¶
Lars Wirzenius <liw@iki.fi>. Modified by Robert Luberda
<robert@debian.org>.
See
dwww(7) for copyrights and stuff.