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.\" @(#)getservent.3 8.3 (Berkeley) 1/12/94 33.\" 34.Dd January 12, 1994 35.Dt GETSERVENT 3 36.Os BSD 4.2 37.Sh NAME 38.Nm getservent , 39.Nm getservbyport , 40.Nm getservbyname , 41.Nm setservent , 42.Nm endservent 43.Nd get service entry 44.Sh SYNOPSIS 45.Fd #include <netdb.h> 46.Ft struct servent * 47.Fn getservent 48.Ft struct servent * 49.Fn getservbyname "char *name" "char *proto" 50.Ft struct servent * 51.Fn getservbyport "int port" proto 52.Ft void 53.Fn setservent "int stayopen" 54.Ft void 55.Fn endservent void 56.Sh DESCRIPTION 57The 58.Fn getservent , 59.Fn getservbyname , 60and 61.Fn getservbyport 62functions 63each return a pointer to an object with the 64following structure 65containing the broken-out 66fields of a line in the network services data base, 67.Pa /etc/services . 68.Bd -literal -offset indent 69struct servent { 70 char *s_name; /* official name of service */ 71 char **s_aliases; /* alias list */ 72 int s_port; /* port service resides at */ 73 char *s_proto; /* protocol to use */ 74}; 75.Ed 76.Pp 77The members of this structure are: 78.Bl -tag -width s_aliases 79.It Fa s_name 80The official name of the service. 81.It Fa s_aliases 82A zero terminated list of alternate names for the service. 83.It Fa s_port 84The port number at which the service resides. 85Port numbers are returned in network byte order. 86.It Fa s_proto 87The name of the protocol to use when contacting the 88service. 89.El 90.Pp 91The 92.Fn getservent 93function 94reads the next line of the file, opening the file if necessary. 95.Pp 96The 97.Fn setservent 98function 99opens and rewinds the file. If the 100.Fa stayopen 101flag is non-zero, 102the net data base will not be closed after each call to 103.Fn getservbyname 104or 105.Fn getservbyport . 106.Pp 107The 108.Fn endservent 109function 110closes the file. 111.Pp 112The 113.Fn getservbyname 114and 115.Fn getservbyport 116functions 117sequentially search from the beginning 118of the file until a matching 119protocol name or 120port number is found, 121or until 122.Dv EOF 123is encountered. 124If a protocol name is also supplied (non- 125.Dv NULL ) , 126searches must also match the protocol. 127.ne 1i 128.Sh FILES 129.Bl -tag -width /etc/services -compact 130.It Pa /etc/services 131.El 132.Sh DIAGNOSTICS 133Null pointer 134(0) returned on 135.Dv EOF 136or error. 137.Sh SEE ALSO 138.Xr getprotoent 3 , 139.Xr services 5 140.Sh HISTORY 141The 142.Fn getservent , 143.Fn getservbyport , 144.Fn getservbyname , 145.Fn setservent , 146and 147.Fn endservent 148functions appeared in 149.Bx 4.2 . 150.Sh BUGS 151These functions use static data storage; 152if the data is needed for future use, it should be 153copied before any subsequent calls overwrite it. 154Expecting port numbers to fit in a 32 bit 155quantity is probably naive. 156