Description |
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The routines inet_addr and inet_network
each interpret character strings representing numbers expressed in
the internet standard "dot" notation, returning numbers suitable for
use as internet addresses and internet network numbers, respectively. Their
return values can be assigned to a struct in_addr (defined in /usr/include/netinet/in.h)
as in the following example:
struct in_addr addr;
char *cp;
addr.s_addr = inet_addr(cp);
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inet_ntoa takes an interet address and returns an ASCII
string representing the address in "dot" (.) notation.
All internet addresses are returned in network order (bytes ordered
from left to right). All network numbers and local address parts
are returned as machine-format integer values. Bytes in HP-UX systems
are ordered from left to right.
Internet Addresses: Values specified using the dot (.) notation take
one of the following forms:
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.
When a three-part address is specified, the last part is interpreted
as a 16-bit quantity and placed in the right-most two bytes of the
network address. This makes the three-part address format convenient
for specifying Class B network addresses as in 128.net.host.
When a two-part address is supplied, the last part is interpreted
as a 24-bit quantity and placed in the right-most three bytes of the
network address. This makes the two-part address format convenient
for specifying Class A network addresses as in net.host.
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 a dot (.) notation can be decimal,
octal, or hexadecimal, as specified in the C language (i.e., a leading
0x or 0X implies hexadecimal; a leading 0 implies octal; otherwise,
the number is interpreted as decimal).
