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.Dd June 4, 1993 29.Dt GETPROTOENT 3 30.Os 31.Sh NAME 32.Nm getprotoent , 33.Nm getprotobynumber , 34.Nm getprotobyname , 35.Nm setprotoent , 36.Nm endprotoent 37.Nd get protocol entry 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In netdb.h 42.Ft struct protoent * 43.Fn getprotoent void 44.Ft struct protoent * 45.Fn getprotobyname "const char *name" 46.Ft struct protoent * 47.Fn getprotobynumber "int proto" 48.Ft void 49.Fn setprotoent "int stayopen" 50.Ft void 51.Fn endprotoent void 52.Sh DESCRIPTION 53The 54.Fn getprotoent , 55.Fn getprotobyname , 56and 57.Fn getprotobynumber 58functions 59each return a pointer to an object with the 60following structure 61containing the broken-out 62fields of a line in the network protocol data base, 63.Pa /etc/protocols . 64.Bd -literal -offset indent 65struct protoent { 66 char *p_name; /* official name of protocol */ 67 char **p_aliases; /* alias list */ 68 int p_proto; /* protocol number */ 69}; 70.Ed 71.Pp 72The members of this structure are: 73.Bl -tag -width p_aliases 74.It Fa p_name 75The official name of the protocol. 76.It Fa p_aliases 77A zero terminated list of alternate names for the protocol. 78.It Fa p_proto 79The protocol number. 80.El 81.Pp 82The 83.Fn getprotoent 84function 85reads the next line of the file, opening the file if necessary. 86.Pp 87The 88.Fn setprotoent 89function 90opens and rewinds the file. 91If the 92.Fa stayopen 93flag is non-zero, 94the net data base will not be closed after each call to 95.Fn getprotobyname 96or 97.Fn getprotobynumber . 98.Pp 99The 100.Fn endprotoent 101function 102closes the file. 103.Pp 104The 105.Fn getprotobyname 106function 107and 108.Fn getprotobynumber 109sequentially search from the beginning 110of the file until a matching 111protocol name or 112protocol number is found, 113or until 114.Dv EOF 115is encountered. 116.Sh RETURN VALUES 117Null pointer returned on 118.Dv EOF 119or error. 120.Sh FILES 121.Bl -tag -width /etc/protocols -compact 122.It Pa /etc/protocols 123.El 124.Sh SEE ALSO 125.Xr protocols 5 126.Sh HISTORY 127The 128.Fn getprotoent , 129.Fn getprotobynumber , 130.Fn getprotobyname , 131.Fn setprotoent , 132and 133.Fn endprotoent 134functions appeared in 135.Bx 4.2 . 136.Sh BUGS 137These functions use a thread-specific data space; 138if the data is needed for future use, it should be 139copied before any subsequent calls overwrite it. 140Only the Internet 141protocols are currently understood. 142