inet_ntop(3) - Man pages

inet_ntop(3)                Library Functions Manual               inet_ntop(3)

NAME
       inet_ntop - convert IPv4 and IPv6 addresses from binary to text form

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <arpa/inet.h>

       const char *inet_ntop(int af, const void *restrict src,
                             char dst[restrict .size], socklen_t size);

DESCRIPTION
       This  function  converts the network address structure src in the af ad-
       dress family into a character string.  The resulting string is copied to
       the buffer pointed to by dst, which must be  a  non-null  pointer.   The
       caller specifies the number of bytes available in this buffer in the ar-
       gument size.

       inet_ntop()  extends  the  inet_ntoa(3) function to support multiple ad-
       dress families, inet_ntoa(3) is now considered to be deprecated in favor
       of inet_ntop().  The following address families are currently supported:

       AF_INET
              src points to a struct in_addr (in network byte order)  which  is
              converted  to  an IPv4 network address in the dotted-decimal for-
              mat, "ddd.ddd.ddd.ddd".  The buffer dst must be at least INET_AD-
              DRSTRLEN bytes long.

       AF_INET6
              src points to a struct in6_addr (in network byte order) which  is
              converted  to a representation of this address in the most appro-
              priate IPv6 network address format for this address.  The  buffer
              dst must be at least INET6_ADDRSTRLEN bytes long.

RETURN VALUE
       On  success, inet_ntop() returns a non-null pointer to dst.  NULL is re-
       turned if there was an error, with errno set to indicate the error.

ERRORS
       EAFNOSUPPORT
              af was not a valid address family.

       ENOSPC The converted address string would exceed the size given by size.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────┬───────────────┬────────────────┐
       │ Interface                           │ Attribute     │ Value          │
       ├─────────────────────────────────────┼───────────────┼────────────────┤
       │ inet_ntop()                         │ Thread safety │ MT-Safe locale │
       └─────────────────────────────────────┴───────────────┴────────────────┘

STANDARDS
       POSIX.1-2008.

HISTORY
       POSIX.1-2001.

       Note that RFC 2553 defines a prototype where the last argument  size  is
       of  type  size_t.  Many systems follow RFC 2553.  glibc 2.0 and 2.1 have
       size_t, but 2.2 and later have socklen_t.

BUGS
       AF_INET6 converts IPv4-mapped IPv6 addresses into an IPv6 format.

EXAMPLES
       See inet_pton(3).

SEE ALSO
       getnameinfo(3), inet(3), inet_pton(3)

Linux man-pages 6.9.1              2024-05-02                      inet_ntop(3)

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