1.\" $NetBSD: getprotoent.3,v 1.13 2011/07/14 22:12:30 wiz 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)getprotoent.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd July 15, 2011 33.Dt GETPROTOENT 3 34.Os 35.Sh NAME 36.Nm getprotoent , 37.Nm getprotobynumber , 38.Nm getprotobyname , 39.Nm setprotoent , 40.Nm endprotoent 41.Nd get protocol entry 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In netdb.h 46.Ft struct protoent * 47.Fn getprotoent 48.Ft struct protoent * 49.Fn getprotobyname "const char *name" 50.Ft struct protoent * 51.Fn getprotobynumber "int proto" 52.Ft void 53.Fn setprotoent "int stayopen" 54.Ft void 55.Fn endprotoent "void" 56.Sh DESCRIPTION 57The 58.Fn getprotoent , 59.Fn getprotobyname , 60and 61.Fn getprotobynumber 62functions 63each return a pointer to an object with the 64following structure 65containing the broken-out 66fields of a line in the network protocol data base, 67.Pa /etc/protocols . 68.Bd -literal -offset indent 69.Pp 70struct protoent { 71 char *p_name; /* official name of protocol */ 72 char **p_aliases; /* alias list */ 73 int p_proto; /* protocol number */ 74}; 75.Ed 76.Pp 77The members of this structure are: 78.Bl -tag -width p_aliases -offset indent 79.It Fa p_name 80The official name of the protocol. 81.It Fa p_aliases 82A zero terminated list of alternative names for the protocol. 83.It Fa p_proto 84The protocol number. 85.El 86.Pp 87The 88.Fn getprotoent 89function 90reads the next line of the file, opening the file if necessary. 91.Pp 92The 93.Fn setprotoent 94function 95opens and rewinds the file. 96If the 97.Fa stayopen 98flag is non-zero, 99the net data base will not be closed after each call to 100.Fn getprotobyname 101or 102.Fn getprotobynumber . 103.Pp 104The 105.Fn endprotoent 106function 107closes the file. 108.Pp 109The 110.Fn getprotobyname 111function 112and 113.Fn getprotobynumber 114sequentially search from the beginning 115of the file until a matching 116protocol name or 117protocol number is found, 118or until 119.Dv EOF 120is encountered. 121.Sh RETURN VALUES 122Upon success, 123.Fn getprotoent , 124.Fn getprotobyname , 125and 126.Fn getprotobynumber 127return a pointer to the 128.Vt protoent 129structure as described above. 130A 131.Dv NULL 132pointer is returned on 133.Dv EOF 134or error. 135.Sh FILES 136.Bl -tag -width /etc/protocols -compact 137.It Pa /etc/protocols 138.El 139.Sh SEE ALSO 140.Xr protocols 5 141.Sh HISTORY 142The 143.Fn getprotoent , 144.Fn getprotobynumber , 145.Fn getprotobyname , 146.Fn setprotoent , 147and 148.Fn endprotoent 149functions appeared in 150.Bx 4.2 . 151.Sh BUGS 152These functions use a static data space; 153if the data is needed for future use, it should be 154copied before any subsequent calls overwrite it. 155Only the Internet 156protocols are currently understood. 157