nbd_aio_peek_command_completed(3)

okay so bestie, welcome to the nbd_aio_peek_command_completed(3) page from the LIBNBD manual 🌈 this one is short and cute, and it's basically the vibe check for “did any async command finish yet?” 💅

✨ NAME ✨

nbd_aio_peek_command_completed - check if any command has completed 🎀

📎 SYNOPSIS 📎

#include <libnbd.h>

int64_t nbd_aio_peek_command_completed (
          struct nbd_handle *h
        );

🍓 DESCRIPTION 🍓

okay so here's the tea, no cap: this returns the unique positive 64 bit cookie of the first non-retired but completed command. If there are in-flight commands but none of them are awaiting retirement, it returns 0. If there's an error — including when there are no in-flight commands — it returns -1. 💀

Important bestie moment: any cookie returned by this function must still be passed to nbd_aio_command_completed(3) to actually retire the command and learn whether the command was successful. don't skip that step, iykyk 🫶

👑 RETURN VALUE 👑

This call returns a 64 bit signed integer ≥ 0. periodt 👑

💀 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 1.0. 🎀

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

#define LIBNBD_HAVE_NBD_AIO_PEEK_COMMAND_COMPLETED 1

🦋 SEE ALSO 🦋

• nbd_aio_command_completed(3)
• nbd_create(3)
• libnbd(3)

🌸 AUTHORS 🌸

• Eric Blake
• Richard W.M. Jones

💜 COPYRIGHT 💜

Copyright Red Hat

⭐ LICENSE ⭐

okay legal bestie moment, here's the whole license, no edits, no skipping:

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

mwah 💋 — this page is from libnbd-1.25.8, dated 2026-10-13, and it's the nbd_aio_peek_command_completed(3) page. bye bestie 🫶✨