inet_aton inet_addr inet_network inet_ntoa inet_ntoa_r inet_ntop inet_pton inet_makeaddr inet_lnaof inet_netof - Internet address manipulation routines
function converts a presentation format address (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 1 if the address was valid for the specified address family, or 0 if the address was not parseable in the specified address family, or -1 if some system error occurred (in which case errno will have been set). This function is presently valid for AF_INET and AF_INET6
routine interprets the specified character string as an Internet address, placing the address into the structure provided. It returns 1 if the string was successfully interpreted, or 0 if the string is invalid. The inet_addr ();
and inet_network ();
functions return numbers suitable for use as Internet addresses and Internet network numbers, respectively.
converts an address Fa *src from network format (usually a struct in_addr or some other binary form, in network byte order) to presentation format (suitable for external display purposes). The Fa size argument specifies the size, in bytes, of the buffer Fa *dst . INET_ADDRSTRLEN and INET6_ADDRSTRLEN define the maximum size required to convert an address of the respective type. 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. This function is presently valid for AF_INET and AF_INET6
takes an Internet address and returns an ASCII string representing the address in `.' notation. The routine inet_ntoa_r ();
is the reentrant version of inet_ntoa (.);
The routine inet_makeaddr ();
takes an Internet network number and a local network address and constructs an Internet address from it. The routines inet_netof ();
and inet_lnaof ();
break apart Internet host addresses, returning the network number and local network address part, respectively.
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 address. Note that when an Internet address is viewed as a 32-bit integer quantity on the VAX the bytes referred to above appear as ``d.c.b.a '' That is, VAX bytes are ordered from right to left.
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 ``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 ``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 `.' 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; otherwise, the number is interpreted as decimal).
function should return a Fa struct in_addr .