|INET(3C)||Standard C Library Functions||INET(3C)|
const char *
const void *addr, char *cp,
const char *cp, void *addr);
inet_aton(const char *cp,
struct in_addr *addr);
inet_addr(const char *cp);
inet_makeaddr(const int net,
const int lna);
inet_lnaof(const struct in_addr
inet_netof(const struct in_addr
inet_ntoa(const struct in_addr
inet_pton() functions can manipulate both IPv4 and IPv6 addresses. The
inet_ntoa() functions can only manipulate IPv4 addresses.
inet_ntop() function converts a
numeric address into a string suitable for presentation. The
af argument specifies the family of the address which
The addr argument points to a buffer that holds an
IPv4 address if the af argument is
AF_INET. The addr argument
points to a buffer that holds an IPv6 address if the
af argument is
address must be in network byte order. The cp argument
points to a buffer where the function stores the resulting string. The
application must specify a non-NULL cp argument. The
size argument specifies the size of this buffer. For
IPv6 addresses, the buffer must be at least 46-octets. For IPv4 addresses,
the buffer must be at least 16-octets. To allow applications to easily
declare buffers of the proper size to store IPv4 and IPv6 addresses in
string form, the following two constants are defined in
#define INET_ADDRSTRLEN 16 #define INET6_ADDRSTRLEN 46
inet_pton() function converts the
standard text presentation form of a function to the numeric binary form.
The af argument specifies the family of the address.
AF_INET6 address families are supported. The
cp argument points to the string being passed in. The
addr argument points to a buffer where the function
stores the numeric address. The calling application must ensure that the
buffer referred to by addr is large enough to hold the
numeric address, at least 4 bytes for
AF_INET or 16
inet_network() functions interpret character strings
that represent numbers expressed in the IPv4 standard
.’ notation, returning numbers
suitable for use as IPv4 addresses and IPv4 network numbers, respectively.
inet_makeaddr() function uses an IPv4 network
number and a local network address to construct an IPv4 address. The
inet_lnaof() functions break apart IPv4 host
addresses, then return the network number and local network address,
inet_ntoa() function returns a pointer
to a string in the base 256 notation
d.d.d.d’. See the following section
on IPv4 addresses.
Internet addresses are returned in network order, bytes ordered from left to right. Network numbers and local address parts are returned as machine format integer values.
x:x:x:x:x:x:x:x’, where the
x's are the hexadecimal values of the eight 16-bit pieces of the address. For example, ‘
It is not necessary to write the leading zeros in an individual field. There must be at least one numeral in every field, except when the special syntax described in the following is used.
::’ indicates multiple groups of 16 bits of zeros. The ‘
::’ may only appear once in an address. The ‘
::’ can also be used to compress the leading and trailing zeros in an address. For example, ‘
x:x:x:x:x:x:d.d.d.d’ is sometimes more convenient when dealing with a mixed environment of IPv4 and IPv6 nodes. The
x's in this form represent the hexadecimal values of the six high-order 16-bit pieces of the address. The
d's represent the decimal values of the four low-order 8-bit pieces of the standard IPv4 address. For example:
::FFFF:126.96.36.199 . ::188.8.131.52
::d.d.d.d’ pieces are the general
forms of an IPv4-mapped IPv6 address and an IPv4-compatible IPv6
The IPv4 portion must be in the
d.d.d.d’ form. The following
forms are invalid:
::FFFF:d.d.d ::FFFF:d.d ::d.d.d ::d.d
::FFFF:d’ form is a
valid but unconventional representation of the IPv4-compatible IPv6
corresponds to the general IPv6 address
.’ notation take one of the following forms:
d.d.d.d d.d.d d.d d
When four parts are specified, each part is interpreted as a byte of data and assigned from left to right to the four bytes of an IPv4 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. The three part address format is convenient for
specifying Class B network addresses such as
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. The two part address format is convenient for specifying Class A
network addresses such as
When only one part is given, the value is stored directly in the network address without any byte rearrangement.
With the exception of
supplied as parts in ‘
.’ notation may
be decimal, octal, or hexadecimal, as specified in C language. For example,
a leading ‘
0X’ implies hexadecimal. A leading
0’ implies octal. Otherwise, the
number is interpreted as decimal.
For IPv4 addresses,
only a string in standard IPv4 dot notation
Each number has one to three digits with a decimal value between 0 and 255.
inet_addr() function has been
inet_aton() function returns nonzero if the address is valid,
0if the address is invalid.
inet_ntop() function returns a pointer
to the buffer that contains a string if the conversion succeeds. Otherwise,
NULL is returned. Upon failure,
errno is set to
if the af argument is invalid or
ENOSPC if the size of the result buffer is
inet_pton() function returns
1 if the conversion succeeds,
0 if the input is not a valid IPv4 dotted-decimal
string or a valid IPv6 address string. The function returns
-1 with errno set to
EAFNOSUPPORT if the af
argument is unknown.
INADDR_NONE, which is equivalent
(in_addr_t)(-1), is returned by
inet_network() for malformed requests.
inet_lnaof() break apart IPv4 host addresses,
returning the network number and local network address part,
inet_ntoa() returns a pointer
to a string in the base 256 notation
d.d.d.d’, described in the section on
inet_network() functions are Committed. The
inet_network() functions are Obsolete Committed.
inet_ntoa() points to a buffer which is overwritten on each call. This buffer is implemented as thread-specific data in multithreaded applications.
IPv4-mapped addresses are not recommended.
A simple way to specify Class C network addresses in a manner similar to that for Class B and Class A is needed.
|July 22, 2018||OmniOS|