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 1.2 2003/06/17 04:26:44 dillon 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 73.Pp 74struct protoent { 75 char *p_name; /* official name of protocol */ 76 char **p_aliases; /* alias list */ 77 int p_proto; /* protocol number */ 78}; 79.Ed 80.Pp 81The members of this structure are: 82.Bl -tag -width p_aliases 83.It Fa p_name 84The official name of the protocol. 85.It Fa p_aliases 86A zero terminated list of alternate names for the protocol. 87.It Fa p_proto 88The protocol number. 89.El 90.Pp 91The 92.Fn getprotoent 93function 94reads the next line of the file, opening the file if necessary. 95.Pp 96The 97.Fn setprotoent 98function 99opens and rewinds the file. If the 100.Fa stayopen 101flag is non-zero, 102the net data base will not be closed after each call to 103.Fn getprotobyname 104or 105.Fn getprotobynumber . 106.Pp 107The 108.Fn endprotoent 109function 110closes the file. 111.Pp 112The 113.Fn getprotobyname 114function 115and 116.Fn getprotobynumber 117sequentially search from the beginning 118of the file until a matching 119protocol name or 120protocol number is found, 121or until 122.Dv EOF 123is encountered. 124.Sh RETURN VALUES 125Null pointer 126(0) returned on 127.Dv EOF 128or error. 129.Sh FILES 130.Bl -tag -width /etc/protocols -compact 131.It Pa /etc/protocols 132.El 133.Sh SEE ALSO 134.Xr protocols 5 135.Sh HISTORY 136The 137.Fn getprotoent , 138.Fn getprotobynumber , 139.Fn getprotobyname , 140.Fn setprotoent , 141and 142.Fn endprotoent 143functions appeared in 144.Bx 4.2 . 145.Sh BUGS 146These functions use a static data space; 147if the data is needed for future use, it should be 148copied before any subsequent calls overwrite it. 149Only the Internet 150protocols are currently understood. 151