nbdkit-count-filter(1)

NAME
nbdkit-count-filter - count bytes read, written, zeroed and trimmed

SYNOPSIS
 nbdkit -fv --filter=count plugin

DESCRIPTION
"nbdkit-count-filter" is a filter for nbdkit(1) that simply counts the number of bytes that are read, written, zeroed and trimmed, and reports this number in debugging output when the filter is unloaded (usually when nbdkit exits). The filter output can only be seen when debugging is enabled (-v) which usually implies using the foreground (-f) option as well.

This is a very simple and lightweight filter. For much more comprehensive stats and logging of operations, use nbdkit-stats-filter(1) or nbdkit-log-filter(1) instead.

EXAMPLE
 $ nbdkit -fv null 4k --filter=count \
          --run 'nbdsh -u "$uri" -c "h.pread(4096,0)"'
 [lots of output]
 nbdkit: debug: null: unload plugin
 nbdkit: debug: count: unload filter
 nbdkit: debug: count bytes: read 4096, written 0, zeroed 0, trimmed 0

PARAMETERS
There are no parameters specific to this filter. All parameters are passed through to the underlying plugin.

FILES

$filterdir/nbdkit-count-filter.so
    The filter.

    Use "nbdkit --dump-config" to find the location of $filterdir.

VERSION
"nbdkit-count-filter" first appeared in nbdkit 1.46.

SEE ALSO
nbdkit(1), nbdkit-file-plugin(1), nbdkit-log-filter(1), nbdkit-stats-filter(1), nbdkit-filter(3).

AUTHORS
Richard W.M. Jones

COPYRIGHT
Copyright Red Hat

LICENSE
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

•   Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

•   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

•   Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.