mirror of https://github.com/mkerrisk/man-pages
131 lines
3.8 KiB
Groff
131 lines
3.8 KiB
Groff
.\" Hey Emacs! This file is -*- nroff -*- source.
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.\"
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.\" Copyright 2002 Ian Redfern (redferni@logica.com)
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.\"
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.\" Permission is granted to make and distribute verbatim copies of this
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.\" manual provided the copyright notice and this permission notice are
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.\" preserved on all copies.
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.\"
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.\" Permission is granted to copy and distribute modified versions of this
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.\" manual under the conditions for verbatim copying, provided that the
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.\" entire resulting derived work is distributed under the terms of a
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.\" permission notice identical to this one.
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.\"
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.\" Since the Linux kernel and libraries are constantly changing, this
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.\" manual page may be incorrect or out-of-date. The author(s) assume no
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.\" responsibility for errors or omissions, or for damages resulting from
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.\" the use of the information contained herein. The author(s) may not
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.\" have taken the same level of care in the production of this manual,
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.\" which is licensed free of charge, as they might when working
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.\" professionally.
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.\"
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.\" Formatted or processed versions of this manual, if unaccompanied by
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.\" the source, must acknowledge the copyright and authors of this work.
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.\"
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.\" References consulted:
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.\" Linux libc source code
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.\" FreeBSD 4.4 man pages
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.\"
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.\" Minor additions, aeb, 2002-07-20
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.\"
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.TH ETHER_ATON 3 2002-07-20 "GNU" "Linux Programmer's Manual"
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.SH NAME
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ether_aton, ether_ntoa, ether_ntohost, ether_hostton, ether_line,
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ether_ntoa_r, ether_aton_r \- Ethernet address manipulation routines
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.SH SYNOPSIS
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.nf
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.B #include <netinet/ether.h>
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.sp
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.BI "char *ether_ntoa(const struct ether_addr *" addr );
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.sp
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.BI "struct ether_addr *ether_aton(const char *" asc );
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.sp
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.BI "int ether_ntohost(char *" hostname ", const struct ether_addr *" addr );
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.sp
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.BI "int ether_hostton(const char *" hostname ", struct ether_addr *" addr );
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.sp
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.BI "int ether_line(const char *" line ", struct ether_addr *" addr ,
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.BI " char *" hostname );
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.sp
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/* GNU extensions */
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.br
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.BI "char *ether_ntoa_r(const struct ether_addr *" addr ", char *" buf );
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.sp
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.BI "struct ether_addr *ether_aton_r(const char *" asc ,
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.BI " struct ether_addr *" addr );
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.fi
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.SH DESCRIPTION
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.BR ether_aton ()
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converts the 48-bit Ethernet host address \fIasc\fP
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from the standard hex-digits-and-colons notation into binary data in
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network byte order and returns a pointer to it in a statically
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allocated buffer, which subsequent calls will
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overwrite.
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.BR ether_aton ()
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returns NULL if the address is invalid.
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.PP
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The
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.BR ether_ntoa ()
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function converts the Ethernet host address
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\fIaddr\fP given in network byte order to a string in standard
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hex-digits-and-colons notation, omitting leading zeros.
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The string is returned in a statically allocated buffer,
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which subsequent calls will overwrite.
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.PP
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The
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.BR ether_ntohost ()
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function maps an Ethernet address to the
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corresponding hostname in
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.I /etc/ethers
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and returns nonzero if it cannot be found.
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.PP
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The
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.BR ether_hostton ()
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function maps a hostname to the
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corresponding Ethernet address in
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.I /etc/ethers
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and returns nonzero if it cannot be found.
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.PP
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The
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.BR ether_line ()
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function parses a line in
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.I /etc/ethers
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format (ethernet address followed by whitespace followed by
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hostname; \(aq#\(aq introduces a comment) and returns an address
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and hostname pair, or nonzero if it cannot be parsed.
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The buffer pointed to by
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.I hostname
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must be sufficiently long, for example, have the same length as
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.IR line .
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.PP
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The functions
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.BR ether_ntoa_r ()
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and
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.BR ether_aton_r ()
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are reentrant
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thread-safe versions of
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.BR ether_ntoa ()
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and
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.BR ether_aton ()
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respectively, and do not use static buffers.
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.PP
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The structure \fIether_addr\fP is defined in
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.I <net/ethernet.h>
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as:
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.sp
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.in +4n
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.nf
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struct ether_addr {
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uint8_t ether_addr_octet[6];
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}
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.fi
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.in
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.SH "CONFORMING TO"
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4.3BSD, SunOS.
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.SH BUGS
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The glibc 2.2.5 implementation of
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.BR ether_line ()
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is broken.
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.SH "SEE ALSO"
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.BR ethers (5)
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