'\" te
.\" Copyright 1989 AT&T.
.\" Copyright (C) 2004, Sun Microsystems, Inc. All Rights Reserved.
.TH ethers 3SOCKET "10 Dec 2009" "SunOS 5.11" "Sockets Library Functions"
.SH NAME
ethers, ether_ntoa, ether_aton, ether_ntohost, ether_hostton, ether_line \- Ethernet address mapping operations
.SH SYNOPSIS
.LP
.nf
\fBcc\fR [ \fIflag\fR ... ] \fIfile\fR ... \fB-lsocket\fR \fB -lnsl \fR [ \fIlibrary\fR ... ]
#include <sys/types.h>
#include <sys/ethernet.h>

\fBchar *\fR\fBether_ntoa\fR(\fBconst struct ether_addr *\fR\fIe\fR);
.fi

.LP
.nf
\fBstruct ether_addr *\fR\fBether_aton\fR(\fBconst char *\fR\fIs\fR);
.fi

.LP
.nf
\fBint\fR \fBether_ntohost\fR(\fBchar *\fR\fIhostname\fR, \fBconst struct ether_addr *\fR\fIe\fR);
.fi

.LP
.nf
\fBint\fR \fBether_hostton\fR(\fBconst char *\fR\fIhostname\fR, \fBstruct ether_addr *\fR\fIe\fR);
.fi

.LP
.nf
\fBint\fR \fBether_line\fR(\fBconst char *\fR\fIl\fR, \fBstruct ether_addr *\fR\fIe\fR, \fBchar *\fR\fIhostname\fR);
.fi

.SH DESCRIPTION
.sp
.LP
These routines are useful for mapping 48 bit Ethernet numbers to their ASCII representations or their corresponding  host names, and vice versa.
.sp
.LP
The function \fBether_ntoa()\fR converts a 48 bit Ethernet number pointed to by  \fIe\fR to its standard  \fBASCII\fR representation; it returns a pointer to the  \fBASCII\fR string.  The representation is of the form \fIx\fR\|:\|\fIx\fR\|:\|\fIx\fR\|:\| \fIx\fR\|:\|\fIx\fR\|:\|\fIx\fR where  \fIx\fR is a hexadecimal number between \fB0\fR and \fBff\fR.  The function  \fBether_aton()\fR converts an \fBASCII\fR string in the standard representation back to a 48 bit Ethernet number;  the function returns  \fINULL\fR if the string cannot be scanned successfully.
.sp
.LP
The function \fBether_ntohost()\fR maps an Ethernet number (pointed to by \fIe\fR) to its associated hostname.  The string pointed to by hostname must be long enough to hold the  hostname and a  \fINULL\fR character.  The function returns zero upon success and non-zero upon failure.  Inversely, the function \fBether_hostton()\fR maps a hostname string to its corresponding Ethernet number; the function modifies the  Ethernet number pointed to by \fIe\fR. The function also returns zero upon success and non-zero upon failure. In order to do the mapping, both these functions may lookup one or more of the following sources: the ethers file, and the \fBNIS\fR maps \fBethers.byname\fR and \fBethers.byaddr\fR. The sources and their lookup order are specified in the  \fB/etc/nsswitch.conf\fR file. See \fBnsswitch.conf\fR(4) for details.
.sp
.LP
The function  \fBether_line()\fR scans a line, pointed to by \fIl\fR, and sets the hostname and the Ethernet number, pointed to by \fIe\fR. The string pointed to by hostname must be long enough to hold the hostname and a  \fINULL\fR character.  The function returns zero upon success and non-zero upon failure.  The format of the scanned line is described by  \fBethers\fR(4).
.SH FILES
.sp
.ne 2
.mk
.na
\fB\fB/etc/ethers\fR\fR
.ad
.RS 22n
.rt  
Ethernet address to hostname database or domain
.RE

.sp
.ne 2
.mk
.na
\fB\fB/etc/nsswitch.conf\fR\fR
.ad
.RS 22n
.rt  
configuration file for the name service switch
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
MT-LevelMT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBethers\fR(4), \fBnsswitch.conf\fR(4), \fBattributes\fR(5)