1INET_NTOP(3) Linux Programmer's Manual INET_NTOP(3)
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6 inet_ntop - convert IPv4 and IPv6 addresses from binary to text form
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9 #include <arpa/inet.h>
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11 const char *inet_ntop(int af, const void *restrict src,
12 char *restrict dst, socklen_t size);
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15 This function converts the network address structure src in the af ad‐
16 dress family into a character string. The resulting string is copied
17 to the buffer pointed to by dst, which must be a non-null pointer. The
18 caller specifies the number of bytes available in this buffer in the
19 argument size.
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21 inet_ntop() extends the inet_ntoa(3) function to support multiple ad‐
22 dress families, inet_ntoa(3) is now considered to be deprecated in fa‐
23 vor of inet_ntop(). The following address families are currently sup‐
24 ported:
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26 AF_INET
27 src points to a struct in_addr (in network byte order) which is
28 converted to an IPv4 network address in the dotted-decimal for‐
29 mat, "ddd.ddd.ddd.ddd". The buffer dst must be at least
30 INET_ADDRSTRLEN bytes long.
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32 AF_INET6
33 src points to a struct in6_addr (in network byte order) which is
34 converted to a representation of this address in the most appro‐
35 priate IPv6 network address format for this address. The buffer
36 dst must be at least INET6_ADDRSTRLEN bytes long.
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39 On success, inet_ntop() returns a non-null pointer to dst. NULL is re‐
40 turned if there was an error, with errno set to indicate the error.
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43 EAFNOSUPPORT
44 af was not a valid address family.
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46 ENOSPC The converted address string would exceed the size given by
47 size.
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50 For an explanation of the terms used in this section, see at‐
51 tributes(7).
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53 ┌─────────────────────────────────────┬───────────────┬────────────────┐
54 │Interface │ Attribute │ Value │
55 ├─────────────────────────────────────┼───────────────┼────────────────┤
56 │inet_ntop() │ Thread safety │ MT-Safe locale │
57 └─────────────────────────────────────┴───────────────┴────────────────┘
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60 POSIX.1-2001, POSIX.1-2008. Note that RFC 2553 defines a prototype
61 where the last argument size is of type size_t. Many systems follow
62 RFC 2553. Glibc 2.0 and 2.1 have size_t, but 2.2 and later have
63 socklen_t.
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66 AF_INET6 converts IPv4-mapped IPv6 addresses into an IPv6 format.
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69 See inet_pton(3).
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72 getnameinfo(3), inet(3), inet_pton(3)
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75 This page is part of release 5.12 of the Linux man-pages project. A
76 description of the project, information about reporting bugs, and the
77 latest version of this page, can be found at
78 https://www.kernel.org/doc/man-pages/.
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82Linux 2021-03-22 INET_NTOP(3)