freebsd-nq/lib/libc/sys/getdtablesize.2
Jilles Tjoelker e160aec9a5 getdtablesize(2): Describe what this function actually does.
getdtablesize() returns the limit on new file descriptors; this says nothing
about existing descriptors.

MFC after:	1 week
2013-04-24 21:24:35 +00:00

63 lines
2.3 KiB
Groff

.\" Copyright (c) 1983, 1991, 1993
.\" The Regents of the University of California. 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.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
.\"
.\" @(#)getdtablesize.2 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd April 24, 2013
.Dt GETDTABLESIZE 2
.Os
.Sh NAME
.Nm getdtablesize
.Nd get file descriptor limit
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn getdtablesize void
.Sh DESCRIPTION
The
.Fn getdtablesize
system call returns the maximum number of file descriptors
that the current process may open.
The maximum file descriptor number that the system may assign
is the return value minus one.
Existing file descriptor numbers may be higher
if the limit was lowered after they were opened.
.Sh SEE ALSO
.Xr close 2 ,
.Xr closefrom 2 ,
.Xr dup 2 ,
.Xr getrlimit 2 ,
.Xr sysconf 2
.Sh HISTORY
The
.Fn getdtablesize
system call appeared in
.Bx 4.2 .