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.\" $FreeBSD$ 34.\" 35.Dd June 4, 1993 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 void 49.Ft struct protoent * 50.Fn getprotobyname "const char *name" 51.Ft struct protoent * 52.Fn getprotobynumber "int proto" 53.Ft void 54.Fn setprotoent "int stayopen" 55.Ft void 56.Fn endprotoent void 57.Sh DESCRIPTION 58The 59.Fn getprotoent , 60.Fn getprotobyname , 61and 62.Fn getprotobynumber 63functions 64each return a pointer to an object with the 65following structure 66containing the broken-out 67fields of a line in the network protocol data base, 68.Pa /etc/protocols . 69.Bd -literal -offset indent 70.Pp 71struct protoent { 72 char *p_name; /* official name of protocol */ 73 char **p_aliases; /* alias list */ 74 int p_proto; /* protocol number */ 75}; 76.Ed 77.Pp 78The members of this structure are: 79.Bl -tag -width p_aliases 80.It Fa p_name 81The official name of the protocol. 82.It Fa p_aliases 83A zero terminated list of alternate names for the protocol. 84.It Fa p_proto 85The protocol number. 86.El 87.Pp 88The 89.Fn getprotoent 90function 91reads the next line of the file, opening the file if necessary. 92.Pp 93The 94.Fn setprotoent 95function 96opens and rewinds the file. If 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 122Null pointer 123(0) returned on 124.Dv EOF 125or error. 126.Sh FILES 127.Bl -tag -width /etc/protocols -compact 128.It Pa /etc/protocols 129.El 130.Sh SEE ALSO 131.Xr protocols 5 132.Sh HISTORY 133The 134.Fn getprotoent , 135.Fn getprotobynumber , 136.Fn getprotobyname , 137.Fn setprotoent , 138and 139.Fn endprotoent 140functions appeared in 141.Bx 4.2 . 142.Sh BUGS 143These functions use a static data space; 144if the data is needed for future use, it should be 145copied before any subsequent calls overwrite it. 146Only the Internet 147protocols are currently understood. 148