1.\" Copyright (c) 1983, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)getprotoent.3 6.6 (Berkeley) 4/19/91 33.\" $Id: getprotoent.3,v 1.2 1993/08/01 07:45:20 mycroft Exp $ 34.\" 35.Dd April 19, 1991 36.Dt GETPROTOENT 3 37.Os BSD 4.2 38.Sh NAME 39.Nm getprotoent , 40.Nm getprotobynumber , 41.Nm getprotobyname , 42.Nm setprotoent , 43.Nm endprotoent 44.Nd get protocol entry 45.Sh SYNOPSIS 46.Fd #include <netdb.h> 47.Ft struct protoent * 48.Fn getprotoent 49.Ft struct protoent * 50.Fn getprotobyname "char *name" 51.Ft struct protoent * 52.Fn getprotobynumber "int proto" 53.Fn setprotoent "int stayopen" 54.Fn endprotoent 55.Sh DESCRIPTION 56The 57.Fn getprotoent , 58.Fn getprotobyname , 59and 60.Fn getprotobynumber 61functions 62each return a pointer to an object with the 63following structure 64containing the broken-out 65fields of a line in the network protocol data base, 66.Pa /etc/protocols . 67.Bd -literal -offset indent 68.Pp 69struct protoent { 70 char *p_name; /* official name of protocol */ 71 char **p_aliases; /* alias list */ 72 int p_proto; /* protocol number */ 73}; 74.Ed 75.Pp 76The members of this structure are: 77.Bl -tag -width p_aliases 78.It Fa p_name 79The official name of the protocol. 80.It Fa p_aliases 81A zero terminated list of alternate names for the protocol. 82.It Fa p_proto 83The protocol number. 84.El 85.Pp 86The 87.Fn getprotoent 88function 89reads the next line of the file, opening the file if necessary. 90.Pp 91The 92.Fn setprotoent 93function 94opens and rewinds the file. If the 95.Fa stayopen 96flag is non-zero, 97the net data base will not be closed after each call to 98.Fn getprotobyname 99or 100.Fn getprotobynumber . 101.Pp 102The 103.Fn endprotoent 104function 105closes the file. 106.Pp 107The 108.Fn getprotobyname 109function 110and 111.Fn getprotobynumber 112sequentially search from the beginning 113of the file until a matching 114protocol name or 115protocol number is found, 116or until 117.Dv EOF 118is encountered. 119.Sh RETURN VALUES 120Null pointer 121(0) returned on 122.Dv EOF 123or error. 124.Sh FILES 125.Bl -tag -width /etc/protocols -compact 126.It Pa /etc/protocols 127.El 128.Sh SEE ALSO 129.Xr protocols 5 130.Sh HISTORY 131The 132.Fn getprotoent , 133.Fn getprotobynumber , 134.Fn getprotobyname , 135.Fn setprotoent , 136and 137.Fn endprotoent 138functions appeared in 139.Bx 4.2 . 140.Sh BUGS 141These functions use a static data space; 142if the data is needed for future use, it should be 143copied before any subsequent calls overwrite it. 144Only the Internet 145protocols are currently understood. 146