getaddrinfo and getnameinfo are inverse functions of each other. They are network protocol agnostic, and support both IPv4 and IPv6. It is the recommended interface for name resolution in building protocol independent applications and for transitioning legacy IPv4 code to the IPv6 Internet.

getaddrinfo_a(3) - Linux man page The getaddrinfo_a() function performs the same task as getaddrinfo(3), but allows multiple name look-ups to be performed asynchronously, with optional getaddrinfo_a(3) - Linux man page Name. getaddrinfo_a, gai_suspend, gai_error, gai_cancel - asynchronous network address and service translation getaddrinfo_a(3) - Linux manual page - Michael Kerrisk GETADDRINFO_A(3) Linux Programmer's Manual GETADDRINFO_A(3) NAME top getaddrinfo_a, gai_suspend, gai_error, gai_cancel - asynchronous net‐ work address and service translation c - getaddrinfo() - Linux VS Windows - Stack Overflow

These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt, login, exit and more. The GNU C Library is designed to be a backwards compatible, portable, and high performance ISO C library.

Jul 06, 2012 The GNU C Library The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more.

$ ssh hostname reverse mapping checking getaddrinfo for client.example.com [10.0.0.1] failed - POSSIBLE BREAK-IN ATTEMPT! username@hostname password: Resolution There are several ways to resolve this issue:

gethostbyname(3) - Linux manual page Applications should use getaddrinfo(3), getnameinfo(3), and gai_strerror(3) instead. The gethostbyname () function returns a structure of type hostent for the given host name . Here name is either a hostname or an IPv4 address in standard dot notation (as for inet_addr(3) ). ip address using getaddrinfo()