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freebsd/lib/libc/net/getprotoent.3
Alexey Zelkin 25bb73e063 Introduce ".Lb" macro to libc manpages.
More libraries manpages updates following.
2000-04-21 09:42:15 +00:00

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.\" Copyright (c) 1983, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
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.\" This product includes software developed by the University of
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.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
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.\" @(#)getprotoent.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt GETPROTOENT 3
.Os BSD 4.2
.Sh NAME
.Nm getprotoent ,
.Nm getprotobynumber ,
.Nm getprotobyname ,
.Nm setprotoent ,
.Nm endprotoent
.Nd get protocol entry
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <netdb.h>
.Ft struct protoent *
.Fn getprotoent void
.Ft struct protoent *
.Fn getprotobyname "const char *name"
.Ft struct protoent *
.Fn getprotobynumber "int proto"
.Ft void
.Fn setprotoent "int stayopen"
.Ft void
.Fn endprotoent void
.Sh DESCRIPTION
The
.Fn getprotoent ,
.Fn getprotobyname ,
and
.Fn getprotobynumber
functions
each return a pointer to an object with the
following structure
containing the broken-out
fields of a line in the network protocol data base,
.Pa /etc/protocols .
.Bd -literal -offset indent
.Pp
struct protoent {
char *p_name; /* official name of protocol */
char **p_aliases; /* alias list */
int p_proto; /* protocol number */
};
.Ed
.Pp
The members of this structure are:
.Bl -tag -width p_aliases
.It Fa p_name
The official name of the protocol.
.It Fa p_aliases
A zero terminated list of alternate names for the protocol.
.It Fa p_proto
The protocol number.
.El
.Pp
The
.Fn getprotoent
function
reads the next line of the file, opening the file if necessary.
.Pp
The
.Fn setprotoent
function
opens and rewinds the file. If the
.Fa stayopen
flag is non-zero,
the net data base will not be closed after each call to
.Fn getprotobyname
or
.Fn getprotobynumber .
.Pp
The
.Fn endprotoent
function
closes the file.
.Pp
The
.Fn getprotobyname
function
and
.Fn getprotobynumber
sequentially search from the beginning
of the file until a matching
protocol name or
protocol number is found,
or until
.Dv EOF
is encountered.
.Sh RETURN VALUES
Null pointer
(0) returned on
.Dv EOF
or error.
.Sh FILES
.Bl -tag -width /etc/protocols -compact
.It Pa /etc/protocols
.El
.Sh SEE ALSO
.Xr protocols 5
.Sh HISTORY
The
.Fn getprotoent ,
.Fn getprotobynumber ,
.Fn getprotobyname ,
.Fn setprotoent ,
and
.Fn endprotoent
functions appeared in
.Bx 4.2 .
.Sh BUGS
These functions use a static data space;
if the data is needed for future use, it should be
copied before any subsequent calls overwrite it.
Only the Internet
protocols are currently understood.