diff options
| author | Rick Parrish <unitrunker@unitrunker.net> | 2025-12-18 22:12:32 +0000 |
|---|---|---|
| committer | Alexander Ziaee <ziaee@FreeBSD.org> | 2025-12-18 22:19:42 +0000 |
| commit | ca2413d216197fd55f9363d6f65c641ff1aa3ec5 (patch) | |
| tree | 4fb54aa596f2997162f84524e775f36d0f23d603 | |
| parent | 7f3da1f800f77150fab2a07ce9cafdca41b29ee9 (diff) | |
librt/mq_getfd_np.3: Initial manual page
The mq_getfd_np function appeared in FreeBSD 11 with no documentation.
This function dereferences the mqd_t as a pointer to an int.
Relnotes: yes
MFC after: 3 days
Reviewed by: kib (previous), markj, ziaee
Differential Revision: https://reviews.freebsd.org/D43947
| -rw-r--r-- | lib/librt/Makefile | 2 | ||||
| -rw-r--r-- | lib/librt/mq_getfd_np.3 | 57 |
2 files changed, 59 insertions, 0 deletions
diff --git a/lib/librt/Makefile b/lib/librt/Makefile index c755bb123c73..1189636d0416 100644 --- a/lib/librt/Makefile +++ b/lib/librt/Makefile @@ -24,4 +24,6 @@ SYMBOL_MAPS=${.CURDIR}/Symbol.map HAS_TESTS= SUBDIR.${MK_TESTS}+= tests +MAN= mq_getfd_np.3 + .include <bsd.lib.mk> diff --git a/lib/librt/mq_getfd_np.3 b/lib/librt/mq_getfd_np.3 new file mode 100644 index 000000000000..44c29fbdbf73 --- /dev/null +++ b/lib/librt/mq_getfd_np.3 @@ -0,0 +1,57 @@ +.\" +.\" Copyright (c) 2024 Rick Parrish <unitrunker@unitrunker.net> +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.Dd December 18, 2025 +.Dt MQ_GETFD_NP 3 +.Os +.Sh NAME +.Nm mq_getfd_np +.Nd get a file descriptor for an open message queue descriptor +.Sh SYNOPSIS +.Lb librt +.In mqueue.h +.Ft int +.Fn mq_getfd_np "mqd_t mqd" +.Sh DESCRIPTION +The +.Nm +function retrieves the underlying file descriptor +from the given message queue descriptor returned from +.Xr mq_open 2 . +The file descriptor is used by other functions +to refer to that message queue. +The +.Fa mqd +argument must be an open message queue descriptor. +.Sh IMPLEMENTATION NOTES +.Fx +implements retrieval or alteration of message queue attributes +based on the file descriptor. +The open file descriptor is copied into a child after +.Xr fork 2 . +The +.Xr fstat 2 , +.Xr fchmod 2 , +and +.Xr fchown 2 +system calls are supported for the file descriptor. +.Pp +The file descriptor is safe to use so long as +the message queue descriptor remains open. +.Sh RETURN VALUES +Upon successful completion, the function returns a file descriptor. +.Sh ERRORS +The +.Nm +function does not return any errors. +.Sh SEE ALSO +.Xr mq_close 2 , +.Xr mq_open 2 , +.Xr mqueuefs 4 +.Sh HISTORY +Support for the +.Nm +function first appeared in +.Fx 11.0 . |