сетевой адрес и перевод услуг (network address and service translation)
Примечание (Note)
getaddrinfo() supports the address%scope-id notation for
specifying the IPv6 scope-ID.
AI_ADDRCONFIG, AI_ALL, and AI_V4MAPPED are available since glibc
2.3.3. AI_NUMERICSERV is available since glibc 2.3.4.
According to POSIX.1, specifying hints as NULL should cause
ai_flags to be assumed as 0. The GNU C library instead assumes a
value of (AI_V4MAPPED | AI_ADDRCONFIG) for this case, since this
value is considered an improvement on the specification.
