inet_pton()

Преобразовать текстовый адрес хоста в цифровой адрес

Прототип:

#include <sys/socket.h>
#include <arpa/inet.h>
                                       
int inet_pton( int af,
               const char *src,
               void *dst );

Аргументы:

af

The src address's network family; one of:

AF_INET

IPv4 addresses

AF_INET6

IPv6 addresses

src

A pointer to the text host address that you want to convert. The format of the address is interpreted according to af

dst

A pointer to a buffer where the function can store the converted address.

Библиотека:

libc

Описание:

The inet_pton() function converts the standard text representation of the numeric network address (src) into its numeric network byte-order binary form (dst).

The converted address is stored in network byte order in dst. The buffer pointed to by dst must be large enough to hold the numeric address:

AF_INET addresses

IPv4 addresses must be specified in the standard dotted-decimal form:

ddd.ddd.ddd.ddd

where ddd is a one- to three-digit decimal number between 0 and 255.

---

Many existing implementations of inet_addr() and inet_aton() accept nonstandard input: octal numbers, hexadecimal numbers, and fewer than four numbers. The inet_pton() function doesn't accept these formats.

---

AF_INET6 addresses

IPv6 addresses must be specified in one of the following standard formats:

• The preferred form is:

  x:x:x:x:x:x:x:x

  where x is a hexadecimal value for one of the eight 16-bit pieces of the address. For example:

  DEAD:BEEF:7654:3210:FEDC:3210:7654:BA98
  417A:200C:800:8:0:0:0:1080

• A :: can be used once per address to represent multiple groups of 16 zero-bits. For example, the following addresses:

  1080:0:0:0:8:800:200C:417A
  FF01:0:0:0:0:0:0:43
  0:0:0:0:0:0:0:1
  0:0:0:0:0:0:0:0

  can be represented as:

  1080::8:800:200C:417A
  FF01::43
  ::1
  ::

  A convenient format when dealing with mixed IPv4 and IPv6 environments is:

  x:x:x:x:x:x:d.d.d.d

  where x is a hexadecimal value for one of the six high-order 16-bit pieces of the address and d is a decimal value for one of the four low-order 8-bit pieces of the address (standard AF_INET representation). For example:

  0:0:0:0:0:0:13.1.68.3
  0:0:0:0:0:FFFF:129.144.52.38

  Or, in their compressed forms:

  ::13.1.68.3
  ::FFFF:129.144.52.38

Возвращаемое значение:

1

Успешное завершение.

0

The input isn't a valid address.

-1

Возникла ошибка. Код ошибки записан в errno.

Коды ошибок:

EAFNOSUPPORT

The af argument isn't one of the supported networking families.

Примеры:

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <errno.h>
                                       
#define INADDR  "10.1.0.29"
#define IN6ADDR "DEAD:BEEF:7654:3210:FEDC:3210:7654:BA98"
                                       
int main()
{
    struct in_addr  inaddr;
    struct in6_addr in6addr;
    char            buf[INET_ADDRSTRLEN], buf6[INET6_ADDRSTRLEN];
    int             rval;
                                       
    if ( (rval = inet_pton( AF_INET, INADDR, &inaddr )) == 0 )
    {
        printf( "Invalid address: %s\n", INADDR );
        exit( EXIT_FAILURE );
    } else
        if ( rval == -1 )
        {
            perror( "inet_pton" );
            exit( EXIT_FAILURE );
        }
                                       
    if ( inet_ntop( AF_INET, &inaddr, buf, sizeof( buf ) ) != NULL )
        printf( "inet addr: %s\n", buf );
    else {
        perror( "inet_ntop" );
        exit( EXIT_FAILURE );
    }
                                       
    if ( (rval = inet_pton( AF_INET6, IN6ADDR, &in6addr )) == 0 )
    {
        printf( "Invalid address: %s\n", IN6ADDR );
        exit( EXIT_FAILURE );
    } else
        if ( rval == -1 )
        {
            perror( "inet_pton" );
            exit( EXIT_FAILURE );
        }
            
    if ( inet_ntop( AF_INET6, &in6addr, buf6, sizeof( buf6 ) ) != NULL )
        printf( "inet6 addr: %s\n", buf6 );
    else {
        perror( "inet_ntop" );
        exit( EXIT_FAILURE );
    }
                                       
    return (EXIT_SUCCESS);
}

Классификация:

POSIX 1003.1

Точка остановки потока

Нет

Обработчик прерываний

Нет

Обработчик сигналов

Да

В потоке

Да

Тематические ссылки:

inet_ntop()

Основано на: RFC 2373

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