INET_ADDR(3XNET) X/Open Networking Services Library Functions
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(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
endhostent(3XNET),
endnetent(3XNET),
attributes(7),
standards(7) June 10, 2002 INET_ADDR(3XNET)