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INET_NET(3)	       FreeBSD Library Functions Manual		   INET_NET(3)

NAME
     inet_net_ntop, inet_net_pton -- Internet network number manipulation rou-
     tines

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <sys/types.h>
     #include <sys/socket.h>
     #include <netinet/in.h>
     #include <arpa/inet.h>

     char *
     inet_net_ntop(int af, const void *src, int	bits, char *dst, size_t	size);

     int
     inet_net_pton(int af, const char *src, void *dst, size_t size);

DESCRIPTION
     The inet_net_ntop() function converts an Internet network number from
     network format (usually a struct in_addr or some other binary form, in
     network byte order) to CIDR presentation format (suitable for external
     display purposes).	 The bits argument is the number of bits in src	that
     are the network number.  It returns NULL if a system error	occurs (in
     which case, errno will have been set), or it returns a pointer to the
     destination string.

     The inet_net_pton() function converts a presentation format Internet net-
     work number (that is, printable form as held in a character string) to
     network format (usually a struct in_addr or some other internal binary
     representation, in	network	byte order).  It returns the number of bits
     (either computed based on the class, or specified with /CIDR), or -1 if a
     failure occurred (in which	case errno will	have been set.	It will	be set
     to	ENOENT if the Internet network number was not valid).

     The currently supported values for	af are AF_INET and AF_INET6.  The size
     argument is the size of the result	buffer dst.

NETWORK	NUMBERS	(IP VERSION 4)
     Internet network numbers may be specified in one of the following forms:

	   a.b.c.d/bits
	   a.b.c.d
	   a.b.c
	   a.b
	   a

     When four parts are specified, each is interpreted	as a byte of data and
     assigned, from left to right, to the four bytes of	an Internet network
     number.  Note that	when an	Internet network number	is viewed as a 32-bit
     integer quantity on a system that uses little-endian byte order (such as
     the Intel 386, 486, and Pentium processors) the bytes referred to above
     appear as ``d.c.b.a''.  That is, little-endian bytes are ordered from
     right to left.

     When a three part number is specified, the	last part is interpreted as a
     16-bit quantity and placed	in the rightmost two bytes of the Internet
     network number.  This makes the three part	number format convenient for
     specifying	Class B	network	numbers	as ``128.net.host''.

     When a two	part number is supplied, the last part is interpreted as a
     24-bit quantity and placed	in the rightmost three bytes of	the Internet
     network number.  This makes the two part number format convenient for
     specifying	Class A	network	numbers	as ``net.host''.

     When only one part	is given, the value is stored directly in the Internet
     network number without any	byte rearrangement.

     All numbers supplied as ``parts'' in a `.'	notation may be	decimal,
     octal, or hexadecimal, as specified in the	C language (i.e., a leading 0x
     or	0X implies hexadecimal;	otherwise, a leading 0 implies octal; other-
     wise, the number is interpreted as	decimal).

SEE ALSO
     byteorder(3), inet(3), networks(5)

HISTORY
     The inet_net_ntop() and inet_net_pton() functions appeared	in BIND	4.9.4.

FreeBSD	9.3		       February	26, 2006		   FreeBSD 9.3

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | NETWORK NUMBERS (IP VERSION 4) | SEE ALSO | HISTORY

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