IRIX Base Documentation 2002 November/SGI IRIX Base Documentation 2002 November.iso/usr/share/catman/p_man/cat3c/inet.z/inet

Text File | 2002-10-03 | 13.2 KB | 265 lines

IIIINNNNEEEETTTT((((3333NNNN))))                                                              IIIINNNNEEEETTTT((((3333NNNN))))



NNNNAAAAMMMMEEEE
     inet_aton, inet_addr, inet_network, inet_isaddr, inet_ntoa, inet_ntop,
     inet_pton, inet_makeaddr, inet_lnaof, inet_netof - Internet address
     manipulation routines

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
     ####iiiinnnncccclllluuuuddddeeee <<<<ssssyyyyssss////ttttyyyyppppeeeessss....hhhh>>>>
     ####iiiinnnncccclllluuuuddddeeee <<<<ssssyyyyssss////ssssoooocccckkkkeeeetttt....hhhh>>>>
     ####iiiinnnncccclllluuuuddddeeee <<<<nnnneeeettttiiiinnnneeeetttt////iiiinnnn....hhhh>>>>
     ####iiiinnnncccclllluuuuddddeeee <<<<aaaarrrrppppaaaa////iiiinnnneeeetttt....hhhh>>>>

     iiiinnnntttt iiiinnnneeeetttt____aaaattttoooonnnn((((ccccoooonnnnsssstttt cccchhhhaaaarrrr ****ccccpppp,,,, ssssttttrrrruuuucccctttt iiiinnnn____aaaaddddddddrrrr ****ppppiiiinnnn))));;;;

     uuuunnnnssssiiiiggggnnnneeeedddd lllloooonnnngggg iiiinnnneeeetttt____aaaaddddddddrrrr((((ccccoooonnnnsssstttt cccchhhhaaaarrrr ****ccccpppp))));;;;

     uuuunnnnssssiiiiggggnnnneeeedddd lllloooonnnngggg iiiinnnneeeetttt____nnnneeeettttwwwwoooorrrrkkkk((((ccccoooonnnnsssstttt cccchhhhaaaarrrr ****ccccpppp))));;;;

     iiiinnnntttt iiiinnnneeeetttt____iiiissssaaaaddddddddrrrr((((ccccoooonnnnsssstttt cccchhhhaaaarrrr ****ccccpppp,,,, uuuuiiiinnnntttt33332222____tttt ****aaaaddddddddrrrr))));;;;

     cccchhhhaaaarrrr ****iiiinnnneeeetttt____nnnnttttooooaaaa((((ssssttttrrrruuuucccctttt iiiinnnn____aaaaddddddddrrrr iiiinnnn))));;;;

     ccccoooonnnnsssstttt cccchhhhaaaarrrr ****iiiinnnneeeetttt____nnnnttttoooopppp((((iiiinnnntttt aaaaffff,,,, ccccoooonnnnsssstttt vvvvooooiiiidddd ****ssssrrrrcccc,,,, cccchhhhaaaarrrr ****ddddsssstttt,,,, ssssoooocccckkkklllleeeennnn____tttt ssssiiiizzzzeeee))));;;;

     iiiinnnntttt iiiinnnneeeetttt____ppppttttoooonnnn((((iiiinnnntttt aaaaffff,,,, ccccoooonnnnsssstttt cccchhhhaaaarrrr ****ssssrrrrcccc,,,, vvvvooooiiiidddd ****ddddsssstttt))));;;;

     ssssttttrrrruuuucccctttt iiiinnnn____aaaaddddddddrrrr iiiinnnneeeetttt____mmmmaaaakkkkeeeeaaaaddddddddrrrr((((iiiinnnntttt nnnneeeetttt,,,, iiiinnnntttt llllnnnnaaaa))));;;;

     uuuunnnnssssiiiiggggnnnneeeedddd lllloooonnnngggg iiiinnnneeeetttt____llllnnnnaaaaooooffff((((ssssttttrrrruuuucccctttt iiiinnnn____aaaaddddddddrrrr iiiinnnn))));;;;

     uuuunnnnssssiiiiggggnnnneeeedddd lllloooonnnngggg iiiinnnneeeetttt____nnnneeeettttooooffff((((ssssttttrrrruuuucccctttt iiiinnnn____aaaaddddddddrrrr iiiinnnn))));;;;

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     The routines _i_n_e_t__a_t_o_n, _i_n_e_t__a_d_d_r and _i_n_e_t__n_e_t_w_o_r_k interpret character
     strings representing numbers expressed in the Internet standard "." (dot)
     notation.

     The _i_n_e_t__p_t_o_n function converts a presentation format address (that is,
     printable form as held in a character string) to network format (usually
     a _s_t_r_u_c_t _i_n__a_d_d_r or some other internal binary representation, in network
     byte order).  The function returns 1 if the address is valid or 0 if it
     could not be parsed for the given address family.  If the _a_f argument is
     unknown, then -1 is returned with eeeerrrrrrrrnnnnoooo set to EAFNOSUPPORT.  This
     function is presently valid for AF_INET and AF_INET6.  The following
     discussion under INTERNET ADDRESSES is not valid for the function
     iiiinnnneeeetttt____ppppttttoooonnnn , because if its _a_f argument is AF_INET then the _s_r_c string can
     be only in the standard IPv4 dotted decimal form:

          ddd.ddd.ddd.ddd







                                                                        PPPPaaaaggggeeee 1111






IIIINNNNEEEETTTT((((3333NNNN))))                                                              IIIINNNNEEEETTTT((((3333NNNN))))



     where 'ddd' is a one to three digit decimal number between 0 and 255 (see
     the inet_addr() definition).  The iiiinnnneeeetttt____ppppttttoooonnnn () function does not accept
     other formats (such as the octal numbers, hexadecimal numbers, and fewer
     than four numbers that iiiinnnneeeetttt____aaaattttoooonnnn () or iiiinnnneeeetttt____aaaaddddddddrrrr () accepts).  This is a
     narrower input set than that accepted by iiiinnnneeeetttt____aaaattttoooonnnn....

     If the af argument of iiiinnnneeeetttt____ppppttttoooonnnn () is AF_INET6, the _s_r_c string must be in
     one of the following standard IPv6 text forms:

     1.   The preferred form is 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.
          Leading zeros in individual fields can be omitted, but there must be
          at least one  numeral in every field.

     2.   A string of contiguous zero fields in the preferred form can be
          shown as "::".  The "::" can only appear once in an address.
          Unspecified addresses (0:0:0:0:0:0:0:0) may be represented simply as
          "::".

     3.   A third form that is sometimes more convenient when dealing with a
          mixed environment of IPv4 and IPv6 nodes is x:x:x:x:x:x:d.d.d.d,
          where the "x"s are the hexadecimal values of the six high-order 16-
          bit pieces of the address, and the "d"s are the decimal values of
          the four low-order 8-bit pieces of the address (standard IPv4
          representation).

     The _i_n_e_t__a_t_o_n 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 _i_n_e_t__a_d_d_r and _i_n_e_t__n_e_t_w_o_r_k functions return numbers
     suitable for use as Internet addresses and Internet network numbers,
     respectively.

     The function _i_n_e_t__n_t_o_p converts an address from network format (usually a
     _s_t_r_u_c_t _i_n__a_d_d_r or some other binary form, in network byte order) to
     presentation format (suitable for external display purposes).  It returns
     NULL if a system error occurs (in which case, _e_r_r_n_o will have been set),
     or it returns a pointer to the destination string.  The _a_f argument
     specifies the family of the address.  This can be AF_INET or AF_INET6.
     The _s_r_c argument points to a buffer holding an IPv4 address if the _a_f
     argument is AF_INET, or an IPv6 address if the _a_f argument is AF_INET6.
     The _d_s_t argument points to a buffer where the function will store the
     resulting text string; it must not be NULL.  The _s_i_z_e argument specifies
     the size of this buffer, which must be large enough to hold the text
     string(INET_ADDRSTRLEN characters for IPv4, INET6_ADDRSTRLEN characters
     for IPv6).

     To determine if an ASCII string is a valid representation of an IPv4
     address, the function _i_n_e_t__i_s_a_d_d_r may be used.  It takes a pointer to the
     string, cp, and returns a 1 if the address is valid, 0 otherwise.
     Additionally, if the addr parameter is non-NULL, the converted address
     will be stored at the address pointed to by addr.



                                                                        PPPPaaaaggggeeee 2222






IIIINNNNEEEETTTT((((3333NNNN))))                                                              IIIINNNNEEEETTTT((((3333NNNN))))



     The routine _i_n_e_t__n_t_o_a takes an Internet address and returns an ASCII
     string representing the address in "." notation.  The routine
     _i_n_e_t__m_a_k_e_a_d_d_r takes an Internet network number and a local network
     address and constructs an Internet address from it.  The routines
     _i_n_e_t__n_e_t_o_f and _i_n_e_t__l_n_a_o_f break apart Internet host addresses, returning
     the network number and local network address part, respectively.

     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.

IIIINNNNTTTTEEEERRRRNNNNEEEETTTT AAAADDDDDDDDRRRREEEESSSSSSSSEEEESSSS
     Values specified using the "." notation take one of the following forms:
          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.

     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).

DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
     The constant IIIINNNNAAAADDDDDDDDRRRR____NNNNOOOONNNNEEEE is returned by _i_n_e_t__a_d_d_r and _i_n_e_t__n_e_t_w_o_r_k for
     malformed requests.

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     gethostbyname(3N), getnetent(3N), hosts(4), networks(4)

SSSSTTTTAAAANNNNDDDDAAAARRRRDDDDSSSS
     The iiiinnnneeeetttt____nnnnttttoooopppp and iiiinnnneeeetttt____ppppttttoooonnnn functions conform to XNS 5.2 standards.

BBBBUUUUGGGGSSSS
     The value IIIINNNNAAAADDDDDDDDRRRR____NNNNOOOONNNNEEEE (0xffffffff) is a valid broadcast address, but
     _i_n_e_t__a_d_d_r cannot return that value without indicating failure.  The newer
     _i_n_e_t__a_t_o_n function does not share this problem.



                                                                        PPPPaaaaggggeeee 3333






IIIINNNNEEEETTTT((((3333NNNN))))                                                              IIIINNNNEEEETTTT((((3333NNNN))))



     The string returned by _i_n_e_t__n_t_o_a resides in a static memory area.  Thus

          printf("%s %s0, inet_ntoa(addr1), inet_ntoa(addr2));

     will print the same address twice.

     Inet_addr should return a struct in_addr.

     The problem of host byte ordering versus network byte ordering is
     confusing.

     A simple way to specify Class C network addresses in a manner similar to
     that for Class B and Class A is needed.










































                                                                        PPPPaaaaggggeeee 4444