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
argument 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 fa-
vor of inet_ntop(). The following address families are currently sup-
ported:
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_ADDRSTRLEN 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 attrib-
utes(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 6.7 2023-10-31 inet_ntop(3)
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