freebsd-dev/lib/libc/sys/closefrom.2
Mateusz Guzik f3f3e3c44d fd: add close_range(..., CLOSE_RANGE_CLOEXEC)
For compatibility with Linux.

MFC after:	3 days
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D34424
2022-03-03 17:21:58 +00:00

95 lines
2.8 KiB
Groff

.\" Copyright (c) 2009 Hudson River Trading LLC
.\" Written by: John H. Baldwin <jhb@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR 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.
.\"
.\" $FreeBSD$
.\"
.Dd March 3, 2022
.Dt CLOSEFROM 2
.Os
.Sh NAME
.Nm closefrom ,
.Nm close_range
.Nd delete open file descriptors
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft void
.Fn closefrom "int lowfd"
.Ft int
.Fn close_range "u_int lowfd" "u_int highfd" "int flags"
.Sh DESCRIPTION
The
.Fn closefrom
system call deletes all open file descriptors greater than or equal to
.Fa lowfd
from the per-process object reference table.
Any errors encountered while closing file descriptors are ignored.
.Pp
The
.Fn close_range
system call deletes all open file descriptors between
.Fa lowfd
and
.Fa highfd
inclusive, clamped to the range of open file descriptors.
Any errors encountered while closing file descriptors are ignored.
Supported
.Fa flags :
.Bl -tag -width ".Dv CLOSE_RANGE_CLOEXEC"
.It Dv CLOSE_RANGE_CLOEXEC
Set the close-on-exec flag on descriptors in the range instead of closing them.
.El
.Sh RETURN VALUES
Upon successful completion,
.Fn close_range
returns a value
of 0.
Otherwise, a value of -1 is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
The
.Fn close_range
system call
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa highfd
argument is lower than the
.Fa lowfd
argument.
.It Bq Er EINVAL
An invalid flag was set.
.El
.Sh SEE ALSO
.Xr close 2
.Sh HISTORY
The
.Fn closefrom
function first appeared in
.Fx 8.0 .