NAME

nbdkit_debug, nbdkit_vdebug - print debugging messages for nbdkit

SYNOPSIS

 #include <nbdkit-plugin.h>

 void nbdkit_debug (const char *fs, ...);
 void nbdkit_vdebug (const char *fs, va_list args);

DESCRIPTION

Use nbdkit_debug or nbdkit_vdebug to print debug messages from your plugin or filter.

These functions send the debug message to either stderr or the system logs depending on the current server state and the user-specified nbdkit --log option. Debug messages are only emitted when the server is in verbose mode (nbdkit -v option)

nbdkit_debug works like printf(3). nbdkit_vdebug works like vprintf(3).

For convenience both these functions preserve the value of errno, and also support the glibc extension of a single %m in a format string expanding to strerror(errno), even on platforms that don't support that natively.

LANGUAGE BINDINGS

In nbdkit-golang-plugin(3):

 import "libguestfs.org/nbdkit"
 nbdkit.Debug(msg)

In nbdkit-ocaml-plugin(3):

 NBDKit.debug : ('a, unit, string, unit) format4 -> 'a

In nbdkit-perl-plugin(3):

 Nbdkit::debug ($msg);

In nbdkit-python-plugin(3):

 import nbdkit
 nbdkit.debug(str)

In nbdkit-rust-plugin(3):

 use nbdkit::*;
 debug!(fs, ...);

HISTORY

nbdkit_debug was present in nbdkit 0.1.0.

SEE ALSO

nbdkit(1), nbdkit_error(3), nbdkit-plugin(3), 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:

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.