nbd_get_subprocess_pid(3)           LIBNBD           nbd_get_subprocess_pid(3)


NAME
       nbd_get_subprocess_pid - get the process ID of the subprocess

SYNOPSIS
        #include <libnbd.h>

        int64_t nbd_get_subprocess_pid (
                  struct nbd_handle *h
                );

DESCRIPTION
       For connections which create a subprocess such as
       nbd_connect_command(3), this returns the process ID (PID) of the
       subprocess.  This is only supported on some platforms.

       This is mainly useful in debugging cases.  For example, this could be
       used to learn where to attach gdb(1) to diagnose a crash in the NBD
       server subprocess.

RETURN VALUE
       This call returns a 64 bit signed integer >= 0.

ERRORS
       On error -1 is returned.

       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
       of the error.

       The following parameters must not be NULL: "h".  For more information
       see "Non-NULL parameters" in libnbd(3).

VERSION
       This function first appeared in libnbd 1.22.

       If you need to test if this function is available at compile time check
       if the following macro is defined:

        #define LIBNBD_HAVE_NBD_GET_SUBPROCESS_PID 1

SEE ALSO
       nbd_connect_command(3), nbd_create(3), nbd_kill_subprocess(3),
       libnbd(3), fork(2), gdb(1).

AUTHORS
       Eric Blake

       Richard W.M. Jones

COPYRIGHT
       Copyright Red Hat

LICENSE
       This library is free software; you can redistribute it and/or modify it
       under the terms of the GNU Lesser General Public License as published
       by the Free Software Foundation; either version 2 of the License, or
       (at your option) any later version.

       This library is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       Lesser General Public License for more details.

       You should have received a copy of the GNU Lesser General Public
       License along with this library; if not, write to the Free Software
       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
       02110-1301 USA

libnbd-1.22.1                     2025-04-23         nbd_get_subprocess_pid(3)