INET_ADDR(3XNET) X/Open Networking Services Library Functions INET_ADDR(3XNET)


NAME


inet_addr, inet_network, inet_makeaddr, inet_lnaof, inet_netof, inet_ntoa
- Internet address manipulation

SYNOPSIS


cc [ flag ... ] file ... -lxnet [ library ... ]
#include <arpa/inet.h>

in_addr_t inet_addr(const char *cp);


in_addr_t inet_lnaof(struct in_addr in);


struct in_addr inet_makeaddr(in_addr_t net, in_addr_t lna);


in_addr_t inet_netof(struct in_addr in);


in_addr_t inet_network(const char *cp);


char *inet_ntoa(struct in_addr in);


DESCRIPTION


The inet_addr() function converts the string pointed to by cp, in the
Internet standard dot notation, to an integer value suitable for use as
an Internet address.


The inet_lnaof() function takes an Internet host address specified by in
and extracts the local network address part, in host byte order.


The inet_makeaddr() function takes the Internet network number specified
by net and the local network address specified by lna, both in host byte
order, and constructs an Internet address from them.


The inet_netof() function takes an Internet host address specified by in
and extracts the network number part, in host byte order.


The inet_network() function converts the string pointed to by cp, in the
Internet standard dot notation, to an integer value suitable for use as
an Internet network number.


The inet_ntoa() function converts the Internet host address specified by
in to a string in the Internet standard dot notation.


All Internet addresses are returned in network order (bytes ordered from
left to right).


Values specified using dot notation take one of the following forms:

a.b.c.d
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 address.


a.b.c
When a three-part address is specified, the last part is
interpreted as a 16-bit quantity and placed in the rightmost
two bytes of the network address. This makes the three-part
address format convenient for specifying Class B network
addresses as 128.net.host.


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


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


All numbers supplied as parts in dot notation may be decimal, octal, or
hexadecimal, that is, a leading 0x or 0X implies hexadecimal, as
specified in the ISO C standard; otherwise, a leading 0 implies octal;
otherwise, the number is interpreted as decimal.

USAGE


The return value of inet_ntoa() may point to static data that may be
overwritten by subsequent calls to inet_ntoa().

RETURN VALUES


Upon successful completion, inet_addr() returns the Internet address.
Otherwise, it returns (in_addr_t)(-1).


Upon successful completion, inet_network() returns the converted Internet
network number. Otherwise, it returns (in_addr_t)(-1).


The inet_makeaddr() function returns the constructed Internet address.


The inet_lnaof() function returns the local network address part.


The inet_netof() function returns the network number.


The inet_ntoa() function returns a pointer to the network address in
Internet-standard dot notation.

ERRORS


No errors are defined.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO


endhostent(3XNET), endnetent(3XNET), attributes(5), standards(5)


June 10, 2002 INET_ADDR(3XNET)