.\" Copyright 2026 The FreeBSD Foundation
.\"
.\" SPDX-License-Identifier: BSD-2-Clause
.\"
.\" This documentation was written by
.\" Konstantin Belousov <kib@FreeBSD.org> under sponsorship
.\" from the FreeBSD Foundation.
.\"
.Dd Feburary 17, 2026
.Dt UEXTERR_GETTEXT
.Os
.Sh NAME
.Nm uexterr_gettext
.Nd "get string representation of the current extended error"
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In exterr.h
.Ft int
.Fo uexterr_gettext
.Fa "char *buffer"
.Fa "size_t buffer_size"
.Fc
.Sh DESCRIPTION
The
.Nm
function fills the buffer pointed to by the
.Fa buffer
pointer with the formatted extended null-terminated
error string, as reported by the
last error from a system call, which returned an extended error.
The capacity of the passed buffer is
.Va buffer_size
bytes.
.Pp
Normally, applications should use the
.Xr err 3
family of functions to display errors from system calls.
If this is not convenient or even not possible,
for instance for applications with an advanced user interface, the
.Nm
function can be used to fetch the string with the extended error.
.Pp
Note that most parts of the extended errors are directly provided by
the kernel, and as such cannot be localized.
.Pp
See
.Xr exterror 9
for the description of the extended error facilities.
.Sh RETURN VALUES
The
.Fn
function returns zero.
There are currently no errors defined for the function,
which might change in future.
.Pp
If any error condition is added, it will be reported by returning \-1
and setting
.Va errno
to the corresponding value.
.Sh SEE ALSO
.Xr errno 3 ,
.Xr err 3 ,
.Xr exterror 9
.Sh STANDARDS
The
.Nm
is a
.Fx
extension that first appeared in
.Fx 15.0 .