INET_ADDR(P)						     POSIX Programmer's Manual						      INET_ADDR(P)

NAME

       inet_addr, inet_ntoa - IPv4 address manipulation

SYNOPSIS

       #include <arpa/inet.h>

       in_addr_t inet_addr(const char *cp);
       char *inet_ntoa(struct in_addr in);

DESCRIPTION

       The inet_addr() function shall convert the string pointed to by cp, in the standard IPv4 dotted decimal notation, to an integer value suit-
       able for use as an Internet address.

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

       The inet_ntoa() function need not be reentrant. A function that is not required to be reentrant is not required to be thread-safe.

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

       Values specified using IPv4 dotted decimal notation take one of the following forms:

       a.b.c.d
	      When four parts are specified, each shall be 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 shall be 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 shall be 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 shall be stored directly in the network address without any byte rearrangement.

       All numbers supplied as parts in IPv4 dotted decimal notation may be decimal, octal, or hexadecimal, as specified  in  the  ISO C  standard
       (that is, a leading 0x or 0X implies hexadecimal; otherwise, a leading '0' implies octal; otherwise, the number is interpreted as decimal).

RETURN VALUE

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

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

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

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

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       endhostent() , endnetent() , the Base Definitions volume of IEEE Std 1003.1-2001, <arpa/inet.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
       and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can  be  obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003							      INET_ADDR(P)