1.\" $NetBSD: getnetent.3,v 1.3 1995/02/25 06:20:32 cgd Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)getnetent.3 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt GETNETENT 3 38.Os BSD 4.2 39.Sh NAME 40.Nm getnetent , 41.Nm getnetbyaddr , 42.Nm getnetbyname , 43.Nm setnetent , 44.Nm endnetent 45.Nd get network entry 46.Sh SYNOPSIS 47.Fd #include <netdb.h> 48.Ft struct netent * 49.Fn getnetent 50.Ft struct netent * 51.Fn getnetbyname "char *name" 52.Ft struct netent * 53.Fn getnetbyaddr "long net" "int type" 54.Fn setnetent "int stayopen" 55.Fn endnetent 56.Sh DESCRIPTION 57The 58.Fn getnetent , 59.Fn getnetbyname , 60and 61.Fn getnetbyaddr 62functions 63each return a pointer to an object with the 64following structure 65containing the broken-out 66fields of a line in the network data base, 67.Pa /etc/networks . 68.Bd -literal -offset indent 69struct netent { 70 char *n_name; /* official name of net */ 71 char **n_aliases; /* alias list */ 72 int n_addrtype; /* net number type */ 73 unsigned long n_net; /* net number */ 74}; 75.Ed 76.Pp 77The members of this structure are: 78.Bl -tag -width n_addrtype 79.It Fa n_name 80The official name of the network. 81.It Fa n_aliases 82A zero terminated list of alternate names for the network. 83.It Fa n_addrtype 84The type of the network number returned; currently only AF_INET. 85.It Fa n_net 86The network number. Network numbers are returned in machine byte 87order. 88.El 89.Pp 90The 91.Fn getnetent 92function 93reads the next line of the file, opening the file if necessary. 94.Pp 95The 96.Fn setnetent 97function 98opens and rewinds the file. If the 99.Fa stayopen 100flag is non-zero, 101the net data base will not be closed after each call to 102.Fn getnetbyname 103or 104.Fn getnetbyaddr . 105.Pp 106The 107.Fn endnetent 108function 109closes the file. 110.Pp 111The 112.Fn getnetbyname 113function 114and 115.Fn getnetbyaddr 116sequentially search from the beginning 117of the file until a matching 118net name or 119net address and type is found, 120or until 121.Dv EOF 122is encountered. 123Network numbers are supplied in host order. 124.Sh FILES 125.Bl -tag -width /etc/networks -compact 126.It Pa /etc/networks 127.El 128.Sh DIAGNOSTICS 129Null pointer 130(0) returned on 131.Dv EOF 132or error. 133.Sh SEE ALSO 134.Xr networks 5 135.Sh HISTORY 136The 137.Fn getnetent , 138.Fn getnetbyaddr , 139.Fn getnetbyname , 140.Fn setnetent , 141and 142.Fn endnetent 143functions appeared in 144.Bx 4.2 . 145.Sh BUGS 146The data space used by 147these functions is static; if future use requires the data, it should be 148copied before any subsequent calls to these functions overwrite it. 149Only Internet network 150numbers are currently understood. 151Expecting network numbers to fit 152in no more than 32 bits is probably 153naive. 154