1.\" $OpenBSD: getprotoent.3,v 1.8 2000/12/24 00:30:56 aaron Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd June 4, 1993 35.Dt GETPROTOENT 3 36.Os 37.Sh NAME 38.Nm getprotoent , 39.Nm getprotobynumber , 40.Nm getprotobyname , 41.Nm setprotoent , 42.Nm endprotoent 43.Nd get protocol entry 44.Sh SYNOPSIS 45.Fd #include <netdb.h> 46.Ft struct protoent * 47.Fn getprotoent "void" 48.Ft struct protoent * 49.Fn getprotobyname "char *name" 50.Ft struct protoent * 51.Fn getprotobynumber "int proto" 52.Ft void 53.Fn setprotoent "int stayopen" 54.Ft void 55.Fn endprotoent "void" 56.Sh DESCRIPTION 57The 58.Fn getprotoent , 59.Fn getprotobyname , 60and 61.Fn getprotobynumber 62functions each return a pointer to an object with the following structure 63containing the broken-out fields of a line in the network protocol database, 64.Pa /etc/protocols . 65.Bd -literal -offset indent 66.Pp 67struct protoent { 68 char *p_name; /* official name of protocol */ 69 char **p_aliases; /* alias list */ 70 int p_proto; /* protocol number */ 71}; 72.Ed 73.Pp 74The members of this structure are: 75.Bl -tag -width p_aliases 76.It Fa p_name 77The official name of the protocol. 78.It Fa p_aliases 79A zero-terminated list of alternate names for the protocol. 80.It Fa p_proto 81The protocol number. 82.El 83.Pp 84The 85.Fn getprotoent 86function reads the next line of the file, opening the file if necessary. 87.Pp 88The 89.Fn setprotoent 90function opens and rewinds the file. 91If the 92.Fa stayopen 93flag is non-zero, 94the net database will not be closed after each call to 95.Fn getprotobyname 96or 97.Fn getprotobynumber . 98.Pp 99The 100.Fn endprotoent 101function closes the file. 102.Pp 103The 104.Fn getprotobyname 105and 106.Fn getprotobynumber 107functions sequentially search from the beginning of the file until a 108matching protocol name or protocol number is found, or until 109.Dv EOF 110is encountered. 111.Sh RETURN VALUES 112Null pointer (0) returned on 113.Dv EOF 114or error. 115.Sh FILES 116.Bl -tag -width /etc/protocols -compact 117.It Pa /etc/protocols 118.El 119.Sh SEE ALSO 120.Xr protocols 5 121.Sh HISTORY 122The 123.Fn getprotoent , 124.Fn getprotobynumber , 125.Fn getprotobyname , 126.Fn setprotoent , 127and 128.Fn endprotoent 129functions appeared in 130.Bx 4.2 . 131.Sh BUGS 132These functions use a static data space; if the data is needed for future use, 133it should be copied before any subsequent calls overwrite it. 134Only the Internet protocols are currently understood. 135