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:

• 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.