1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. 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.\" @(#)getprotoent.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/net/getprotoent.3,v 1.4.2.4 2001/12/14 18:33:55 ru Exp $ 34.\" $DragonFly: src/lib/libc/net/getprotoent.3,v 1.3 2008/05/01 21:51:43 swildner Exp $ 35.\" 36.Dd June 4, 1993 37.Dt GETPROTOENT 3 38.Os 39.Sh NAME 40.Nm getprotoent , 41.Nm getprotobynumber , 42.Nm getprotobyname , 43.Nm setprotoent , 44.Nm endprotoent 45.Nd get protocol entry 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In netdb.h 50.Ft struct protoent * 51.Fn getprotoent void 52.Ft struct protoent * 53.Fn getprotobyname "const char *name" 54.Ft struct protoent * 55.Fn getprotobynumber "int proto" 56.Ft void 57.Fn setprotoent "int stayopen" 58.Ft void 59.Fn endprotoent void 60.Sh DESCRIPTION 61The 62.Fn getprotoent , 63.Fn getprotobyname , 64and 65.Fn getprotobynumber 66functions 67each return a pointer to an object with the 68following structure 69containing the broken-out 70fields of a line in the network protocol data base, 71.Pa /etc/protocols . 72.Bd -literal -offset indent 73struct protoent { 74 char *p_name; /* official name of protocol */ 75 char **p_aliases; /* alias list */ 76 int p_proto; /* protocol number */ 77}; 78.Ed 79.Pp 80The members of this structure are: 81.Bl -tag -width p_aliases 82.It Fa p_name 83The official name of the protocol. 84.It Fa p_aliases 85A zero terminated list of alternate names for the protocol. 86.It Fa p_proto 87The protocol number. 88.El 89.Pp 90The 91.Fn getprotoent 92function 93reads the next line of the file, opening the file if necessary. 94.Pp 95The 96.Fn setprotoent 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 getprotobyname 103or 104.Fn getprotobynumber . 105.Pp 106The 107.Fn endprotoent 108function 109closes the file. 110.Pp 111The 112.Fn getprotobyname 113function 114and 115.Fn getprotobynumber 116sequentially search from the beginning 117of the file until a matching 118protocol name or 119protocol number is found, 120or until 121.Dv EOF 122is encountered. 123.Sh RETURN VALUES 124Null pointer 125(0) returned on 126.Dv EOF 127or error. 128.Sh FILES 129.Bl -tag -width /etc/protocols -compact 130.It Pa /etc/protocols 131.El 132.Sh SEE ALSO 133.Xr protocols 5 134.Sh HISTORY 135The 136.Fn getprotoent , 137.Fn getprotobynumber , 138.Fn getprotobyname , 139.Fn setprotoent , 140and 141.Fn endprotoent 142functions appeared in 143.Bx 4.2 . 144.Sh BUGS 145These functions use a static data space; 146if the data is needed for future use, it should be 147copied before any subsequent calls overwrite it. 148Only the Internet 149protocols are currently understood. 150