inet_ntop - Man Page
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 address 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 address 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 format, "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 appropriate 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 returned 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
Referenced By
fmt_ip4(3), fmt_ip6(3), gethostbyname(3), getipnodebyname(3), getnameinfo(3), inet(3), inet_pton(3).