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. 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.\" 30.Dd June 4, 1993 31.Dt GETPROTOENT 3 32.Os 33.Sh NAME 34.Nm getprotoent , 35.Nm getprotobynumber , 36.Nm getprotobyname , 37.Nm setprotoent , 38.Nm endprotoent 39.Nd get protocol entry 40.Sh LIBRARY 41.Lb libc 42.Sh SYNOPSIS 43.In netdb.h 44.Ft struct protoent * 45.Fn getprotoent void 46.Ft struct protoent * 47.Fn getprotobyname "const char *name" 48.Ft struct protoent * 49.Fn getprotobynumber "int proto" 50.Ft void 51.Fn setprotoent "int stayopen" 52.Ft void 53.Fn endprotoent void 54.Sh DESCRIPTION 55The 56.Fn getprotoent , 57.Fn getprotobyname , 58and 59.Fn getprotobynumber 60functions 61each return a pointer to an object with the 62following structure 63containing the broken-out 64fields of a line in the network protocol data base, 65.Pa /etc/protocols . 66.Bd -literal -offset indent 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 87reads the next line of the file, opening the file if necessary. 88.Pp 89The 90.Fn setprotoent 91function 92opens and rewinds the file. 93If the 94.Fa stayopen 95flag is non-zero, 96the net data base will not be closed after each call to 97.Fn getprotobyname 98or 99.Fn getprotobynumber . 100.Pp 101The 102.Fn endprotoent 103function 104closes the file. 105.Pp 106The 107.Fn getprotobyname 108function 109and 110.Fn getprotobynumber 111sequentially search from the beginning 112of the file until a matching 113protocol name or 114protocol number is found, 115or until 116.Dv EOF 117is encountered. 118.Sh RETURN VALUES 119Null pointer returned on 120.Dv EOF 121or error. 122.Sh FILES 123.Bl -tag -width /etc/protocols -compact 124.It Pa /etc/protocols 125.El 126.Sh SEE ALSO 127.Xr protocols 5 128.Sh HISTORY 129The 130.Fn getprotoent , 131.Fn getprotobynumber , 132.Fn getprotobyname , 133.Fn setprotoent , 134and 135.Fn endprotoent 136functions appeared in 137.Bx 4.2 . 138.Sh BUGS 139These functions use a thread-specific data space; 140if the data is needed for future use, it should be 141copied before any subsequent calls overwrite it. 142Only the Internet 143protocols are currently understood. 144