xref: /freebsd/lib/libsys/closefrom.2 (revision b59017c5cad90d0f09a59e68c00457b7faf93e7c)
1.\" Copyright (c) 2009 Hudson River Trading LLC
2.\" Written by: John H. Baldwin <jhb@FreeBSD.org>
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24.\" SUCH DAMAGE.
25.\"
26.Dd March 3, 2022
27.Dt CLOSEFROM 2
28.Os
29.Sh NAME
30.Nm closefrom ,
31.Nm close_range
32.Nd delete open file descriptors
33.Sh LIBRARY
34.Lb libc
35.Sh SYNOPSIS
36.In unistd.h
37.Ft void
38.Fn closefrom "int lowfd"
39.Ft int
40.Fn close_range "u_int lowfd" "u_int highfd" "int flags"
41.Sh DESCRIPTION
42The
43.Fn closefrom
44system call deletes all open file descriptors greater than or equal to
45.Fa lowfd
46from the per-process object reference table.
47Any errors encountered while closing file descriptors are ignored.
48.Pp
49The
50.Fn close_range
51system call deletes all open file descriptors between
52.Fa lowfd
53and
54.Fa highfd
55inclusive, clamped to the range of open file descriptors.
56Any errors encountered while closing file descriptors are ignored.
57Supported
58.Fa flags :
59.Bl -tag -width ".Dv CLOSE_RANGE_CLOEXEC"
60.It Dv CLOSE_RANGE_CLOEXEC
61Set the close-on-exec flag on descriptors in the range instead of closing them.
62.El
63.Sh RETURN VALUES
64Upon successful completion,
65.Fn close_range
66returns a value
67of 0.
68Otherwise, a value of -1 is returned and the global variable
69.Va errno
70is set to indicate the error.
71.Sh ERRORS
72The
73.Fn close_range
74system call
75will fail if:
76.Bl -tag -width Er
77.It Bq Er EINVAL
78The
79.Fa highfd
80argument is lower than the
81.Fa lowfd
82argument.
83.It Bq Er EINVAL
84An invalid flag was set.
85.El
86.Sh SEE ALSO
87.Xr close 2
88.Sh HISTORY
89The
90.Fn closefrom
91function first appeared in
92.Fx 8.0 .
93