Manual browser: getaddrinfo(1)
|GETADDRINFO(1)||General Commands Manual||GETADDRINFO(1)|
NAMEgetaddrinfo — resolve names to socket addresses
|getaddrinfo||[-cNnP] [-f family] [-p protocol] [-s service[/protocol]] [-t socktype] [hostname]|
DESCRIPTIONThe getaddrinfo utility resolves host and service names to socket addresses as if with the getaddrinfo(3) routine and formats them to standard 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:
- 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 example, “inet” corresponds with AF_INET.
- Treat the service as numeric and do not attempt service name resolution, as if with the AI_NUMERICSERV flag to getaddrinfo(3).
- Treat the hostname as a numeric address and do not attempt name resolution, as if with the AI_NUMERICHOST flag to getaddrinfo(3).
- 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.
EXIT STATUSThe getaddrinfo utility exits 0 on success, and >0 if an error occurs.
EXAMPLESLook up “www.NetBSD.org”:
$ getaddrinfo www.NetBSD.org dgram inet6 udp 2001:4f8:3:7:2e0:81ff:fe52:9ab6 0 dgram inet udp 184.108.40.206 0 stream inet6 tcp 2001:4f8:3:7:2e0:81ff:fe52:9ab6 0 stream inet tcp 220.127.116.11 0
The port number here is zero because no service was specified.
Look up “morden.NetBSD.org” for stream sockets on port 80, and show the canonical name:
$ getaddrinfo -c -t stream -s 80 morden.NetBSD.org canonname ftp.NetBSD.org stream inet6 tcp 2001:470:1f05:3d::21 80 stream inet tcp 18.104.22.168 80
SEE ALSOdig(1), getent(1), getaddrinfo(3), getnameinfo(3), resolver(3), hosts(5), nsswitch.conf(5), protocols(5), resolv.conf(5), services(5)
HISTORYThe getaddrinfo command first appeared in NetBSD 7.0.
|April 22, 2014||NetBSD 7.0|