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.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getprotoent.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd June 4, 1993 32.Dt GETPROTOENT 3 33.Os 34.Sh NAME 35.Nm getprotoent , 36.Nm getprotobynumber , 37.Nm getprotobyname , 38.Nm setprotoent , 39.Nm endprotoent 40.Nd get protocol entry 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In netdb.h 45.Ft struct protoent * 46.Fn getprotoent void 47.Ft struct protoent * 48.Fn getprotobyname "const char *name" 49.Ft struct protoent * 50.Fn getprotobynumber "int proto" 51.Ft void 52.Fn setprotoent "int stayopen" 53.Ft void 54.Fn endprotoent void 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 68struct protoent { 69 char *p_name; /* official name of protocol */ 70 char **p_aliases; /* alias list */ 71 int p_proto; /* protocol number */ 72}; 73.Ed 74.Pp 75The members of this structure are: 76.Bl -tag -width p_aliases 77.It Fa p_name 78The official name of the protocol. 79.It Fa p_aliases 80A zero terminated list of alternate names for the protocol. 81.It Fa p_proto 82The protocol number. 83.El 84.Pp 85The 86.Fn getprotoent 87function 88reads the next line of the file, opening the file if necessary. 89.Pp 90The 91.Fn setprotoent 92function 93opens and rewinds the file. 94If 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 returned on 121.Dv EOF 122or error. 123.Sh FILES 124.Bl -tag -width /etc/protocols -compact 125.It Pa /etc/protocols 126.El 127.Sh SEE ALSO 128.Xr protocols 5 129.Sh HISTORY 130The 131.Fn getprotoent , 132.Fn getprotobynumber , 133.Fn getprotobyname , 134.Fn setprotoent , 135and 136.Fn endprotoent 137functions appeared in 138.Bx 4.2 . 139.Sh BUGS 140These functions use a thread-specific data space; 141if the data is needed for future use, it should be 142copied before any subsequent calls overwrite it. 143Only the Internet 144protocols are currently understood. 145