getaddrinfo(1) - NetBSD Manual Pages

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GETADDRINFO(1)          NetBSD General Commands Manual          GETADDRINFO(1)

getaddrinfo -- resolve names to socket addresses
getaddrinfo [-cNnP] [-f family] [-p protocol] [-s service[/protocol]] [-t socktype] [hostname]
The getaddrinfo utility resolves host and service names to socket addresses as if with the getaddrinfo(3) routine and formats them to stan- dard output. The output is a sequence of lines of space-separated fields: socket-type address-family protocol [af-specific data ...] For the ``inet'' and ``inet6'' address families, the af-specific data are the IP/IPv6 address and port number. Although the getaddrinfo utility may query the DNS to give answers, depending on the system's nsswitch.conf(5) configuration, it is not intended to be a general-purpose utility to query the DNS; use the dig(1) utility for that. The following options are available: -c Look up a canonical name as if with the AI_CANONNAME flag to getaddrinfo(3) and print it on the first line before the socket addresses. -f family Specify an address family. Address families are named like the AF_... constants for address family numbers in the <sys/socket.h> header file but without the AF_ prefix and lowercase. For exam- ple, ``inet'' corresponds with AF_INET. -N Treat the service as numeric and do not attempt service name res- olution, as if with the AI_NUMERICSERV flag to getaddrinfo(3). -n Treat the hostname as a numeric address and do not attempt name resolution, as if with the AI_NUMERICHOST flag to getaddrinfo(3). -P Return socket addresses intended for use with bind(2), as if with the AI_PASSIVE flag to getaddrinfo(3). By default, the socket addresses are intended for use with connect(2), sendto(2), or sendmsg(2). -p protocol Specify a protocol. Protocols may be numeric, or symbolic as listed in protocols(5). -s service[/protocol] Specify a service to look up. Services may be symbolic or numeric with an optional protocol suffix as listed in services(5). If no service is specified, a hostname must be specified. -t socktype Specify a socket type. Socket types are named like the SOCK_... constants for socket type numbers in the <sys/socket.h> header file but without the SOCK_ prefix and lowercase. For example, ``dgram'' corresponds with SOCK_DGRAM.
The getaddrinfo utility exits 0 on success, and >0 if an error occurs.
Look up ``'': $ getaddrinfo dgram inet6 udp 2001:4f8:3:7:2e0:81ff:fe52:9ab6 0 dgram inet udp 0 stream inet6 tcp 2001:4f8:3:7:2e0:81ff:fe52:9ab6 0 stream inet tcp 0 The port number here is zero because no service was specified. Look up ``'' for stream sockets on port 80, and show the canonical name: $ getaddrinfo -c -t stream -s 80 canonname stream inet6 tcp 2001:470:1f05:3d::21 80 stream inet tcp 80
dig(1), getent(1), getaddrinfo(3), getnameinfo(3), resolver(3), hosts(5), nsswitch.conf(5), protocols(5), resolv.conf(5), services(5)
The getaddrinfo command first appeared in NetBSD 7.0. NetBSD 10.99 April 22, 2014 NetBSD 10.99
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