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diff --git a/man2/getsockopt.2 b/man2/getsockopt.2 new file mode 100644 index 000000000..f673fa7d0 --- /dev/null +++ b/man2/getsockopt.2 @@ -0,0 +1,181 @@ +.\" Copyright (c) 1983, 1991 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. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 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. +.\" +.\" $Id: getsockopt.2,v 1.1 1999/05/24 14:57:04 freitag Exp $ +.\" +.\" Modified Sat Jul 24 16:19:32 1993 by Rik Faith (faith@cs.unc.edu) +.\" Modified Mon Apr 22 02:29:06 1996 by Martin Schulze (joey@infodrom.north.de) +.\" Modified Tue Aug 27 10:52:51 1996 by Andries Brouwer (aeb@cwi.nl) +.\" Modified Thu Jan 23 13:29:34 1997 by Andries Brouwer (aeb@cwi.nl) +.\" Modified Sun Mar 28 21:26:46 1999 by Andries Brouwer (aeb@cwi.nl) +.\" Modified 1999 by Andi Kleen <ak@muc.de>. Removed most stuff because it is in socket.7 +.\" now. +.\" +.TH GETSOCKOPT 2 1999-05-24 "Linux Man Page" "Linux Programmer's Manual" +.SH NAME +getsockopt, setsockopt \- get and set options on sockets +.SH SYNOPSIS +.B #include <sys/types.h> +.br +.B #include <sys/socket.h> +.sp 2 +.BI "int getsockopt(int " s ", int " level ", int " optname , +.BI "void *" optval ", socklen_t *" optlen ); +.sp +.BI "int setsockopt(int " s ", int " level ", int " optname , +.BI "const void *" optval ", socklen_t " optlen ); +.SH DESCRIPTION +.B Getsockopt +and +.B setsockopt +manipulate the +.I options +associated with a socket. Options may exist at multiple +protocol levels; they are always present at the uppermost +.B socket +level. + +When manipulating socket options the level at which the +option resides and the name of the option must be specified. +To manipulate options at the socket level, +.I level +is specified as +.BR SOL_SOCKET . +To manipulate options at any +other level the protocol number of the appropriate protocol +controlling the option is supplied. For example, +to indicate that an option is to be interpreted by the +.B TCP +protocol, +.I level +should be set to the protocol number of +.BR TCP ; +see +.BR getprotoent (3). + +The parameters +.I optval +and +.I optlen +are used to access option values for +.BR setsockopt . +For +.B getsockopt +they identify a buffer in which the value for the +requested option(s) are to be returned. For +.BR getsockopt , +.I optlen +is a value-result parameter, initially containing the +size of the buffer pointed to by +.IR optval , +and modified on return to indicate the actual size of +the value returned. If no option value is +to be supplied or returned, +.I optval +may be NULL. + +.I Optname +and any specified options are passed uninterpreted to the appropriate +protocol module for interpretation. The include file +.I <sys/socket.h> +contains definitions for socket level options, described below. Options at +other protocol levels vary in format and name; consult the appropriate +entries in section 4 of the manual. + +Most socket-level options utilize an +.I int +parameter for +.IR optval . +For +.BR setsockopt , +the parameter should be non-zero to enable a boolean option, or zero if the +option is to be disabled. + +.PP +For a description of the available socket options see +.BR socket (7) +and the appropriate protocol man pages. + +.SH "RETURN VALUE" +On success, zero is returned. On error, \-1 is returned, and +.I errno +is set appropriately. +.SH ERRORS +.TP 10 +.B EBADF +The argument +.I s +is not a valid descriptor. +.TP +.B EFAULT +The address pointed to by +.I optval +is not in a valid part of the process address space. For +.BR getsockopt , +this error may also be returned if +.I optlen +is not in a valid part of the process address space. +.TP +.B EINVAL +.I optlen +invalid in setsockopt +.TP +.B ENOPROTOOPT +The option is unknown at the level indicated. +.TP +.B ENOTSOCK +The argument +.I s +is a file, not a socket. +.SH "CONFORMING TO" +SVr4, 4.4BSD (these system calls first appeared in 4.2BSD). +SVr4 documents additional ENOMEM and ENOSR error codes, but does +not document the +.BR SO_SNDLOWAT ", " SO_RCVLOWAT ", " SO_SNDTIMEO ", " SO_RCVTIMEO +options +.SH NOTE +The fifth argument of +.BR getsockopt " and " setsockopt +is in reality an int [*] (and this is what BSD 4.* and libc4 and libc5 have). +Some POSIX confusion resulted in the present socklen_t, also used by glibc. +See also +.BR accept (2). +.SH BUGS +Several of the socket options should be handled at lower levels of the +system. +.SH "SEE ALSO" +.BR ioctl (2), +.BR socket (2), +.BR getprotoent (3), +.BR protocols (5), +.BR socket (7), +.BR tcp (7), +.BR unix (7) |