Returns the hostname.
p Socket.gethostname #=> "hal"
Note that it is not guaranteed to be able to convert to IP address using gethostbyname, getaddrinfo, etc. If you need local IP address, use Socket.ip_address_list.
Use Addrinfo.getaddrinfo instead. This method is deprecated for the following reasons:
The 3rd element of the result is the address family of the first address. The address families of the rest of the addresses are not returned.
Uncommon address representation: 4/16-bytes binary string to represent IPv4/IPv6 address.
gethostbyname() may take a long time and it may block other threads. (GVL cannot be released since gethostbyname() is not thread safe.)
This method uses gethostbyname() function already removed from POSIX.
This method obtains the host information for hostname.
p Socket.gethostbyname("hal") #=> ["localhost", ["hal"], 2, "\x7F\x00\x00\x01"]
Use Addrinfo#getnameinfo instead. This method is deprecated for the following reasons:
Uncommon address representation: 4/16-bytes binary string to represent IPv4/IPv6 address.
gethostbyaddr() may take a long time and it may block other threads. (GVL cannot be released since gethostbyname() is not thread safe.)
This method uses gethostbyname() function already removed from POSIX.
This method obtains the host information for address.
p Socket.gethostbyaddr([221,186,184,68].pack("CCCC"))
#=> ["carbon.ruby-lang.org", [], 2, "\xDD\xBA\xB8D"]
p Socket.gethostbyaddr([127,0,0,1].pack("CCCC"))
["localhost", [], 2, "\x7F\x00\x00\x01"]
p Socket.gethostbyaddr(([0]*15+[1]).pack("C"*16))
#=> ["localhost", ["ip6-localhost", "ip6-loopback"], 10,
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"]
Obtains address information for nodename:servname.
Note that Addrinfo.getaddrinfo provides the same functionality in an object oriented style.
family should be an address family such as: :INET, :INET6, etc.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the family, and defaults to 0 for the family.
flags should be bitwise OR of Socket::AI_* constants.
Socket.getaddrinfo("www.ruby-lang.org", "http", nil, :STREAM) #=> [["AF_INET", 80, "carbon.ruby-lang.org", "221.186.184.68", 2, 1, 6]] # PF_INET/SOCK_STREAM/IPPROTO_TCP Socket.getaddrinfo("localhost", nil) #=> [["AF_INET", 0, "localhost", "127.0.0.1", 2, 1, 6], # PF_INET/SOCK_STREAM/IPPROTO_TCP # ["AF_INET", 0, "localhost", "127.0.0.1", 2, 2, 17], # PF_INET/SOCK_DGRAM/IPPROTO_UDP # ["AF_INET", 0, "localhost", "127.0.0.1", 2, 3, 0]] # PF_INET/SOCK_RAW/IPPROTO_IP
reverse_lookup directs the form of the third element, and has to be one of below. If reverse_lookup is omitted, the default value is nil.
+true+, +:hostname+: hostname is obtained from numeric address using reverse lookup, which may take a time. +false+, +:numeric+: hostname is the same as numeric address. +nil+: obey to the current +do_not_reverse_lookup+ flag.
If Addrinfo object is preferred, use Addrinfo.getaddrinfo.
Obtains name information for sockaddr.
sockaddr should be one of follows.
packed sockaddr string such as Socket.sockaddr_in(80, “127.0.0.1”)
3-elements array such as [“AF_INET”, 80, “127.0.0.1”]
4-elements array such as [“AF_INET”, 80, ignored, “127.0.0.1”]
flags should be bitwise OR of Socket::NI_* constants.
Note: The last form is compatible with IPSocket#addr and IPSocket#peeraddr.
Socket.getnameinfo(Socket.sockaddr_in(80, "127.0.0.1")) #=> ["localhost", "www"] Socket.getnameinfo(["AF_INET", 80, "127.0.0.1"]) #=> ["localhost", "www"] Socket.getnameinfo(["AF_INET", 80, "localhost", "127.0.0.1"]) #=> ["localhost", "www"]
If Addrinfo object is preferred, use Addrinfo#getnameinfo.
Gets a socket option. These are protocol and system specific, see your local system documentation for details. The option is returned as a Socket::Option object.
level is an integer, usually one of the SOL_ constants such as Socket::SOL_SOCKET, or a protocol level. A string or symbol of the name, possibly without prefix, is also accepted.
optname is an integer, usually one of the SO_ constants, such as Socket::SO_REUSEADDR. A string or symbol of the name, possibly without prefix, is also accepted.
Some socket options are integers with boolean values, in this case getsockopt could be called like this:
reuseaddr = sock.getsockopt(:SOCKET, :REUSEADDR).bool optval = sock.getsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR) optval = optval.unpack "i" reuseaddr = optval[0] == 0 ? false : true
Some socket options are integers with numeric values, in this case getsockopt could be called like this:
ipttl = sock.getsockopt(:IP, :TTL).int optval = sock.getsockopt(Socket::IPPROTO_IP, Socket::IP_TTL) ipttl = optval.unpack1("i")
Option values may be structs. Decoding them can be complex as it involves examining your system headers to determine the correct definition. An example is a +struct linger+, which may be defined in your system headers as:
struct linger { int l_onoff; int l_linger; };
In this case getsockopt could be called like this:
# Socket::Option knows linger structure. onoff, linger = sock.getsockopt(:SOCKET, :LINGER).linger optval = sock.getsockopt(Socket::SOL_SOCKET, Socket::SO_LINGER) onoff, linger = optval.unpack "ii" onoff = onoff == 0 ? false : true
Returns the local address of the socket as a sockaddr string.
TCPServer.open("127.0.0.1", 15120) {|serv| p serv.getsockname #=> "\x02\x00;\x10\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00" }
If Addrinfo object is preferred over the binary string, use BasicSocket#local_address.
Returns the remote address as an array which contains address_family, port, hostname and numeric_address. It is defined for connection oriented socket such as TCPSocket.
If reverse_lookup is true or :hostname, hostname is obtained from numeric_address using reverse lookup. Or if it is false, or :numeric, hostname is the same as numeric_address. Or if it is nil or omitted, obeys to ipsocket.do_not_reverse_lookup. See Socket.getaddrinfo also.
TCPSocket.open("www.ruby-lang.org", 80) {|sock| p sock.peeraddr #=> ["AF_INET", 80, "carbon.ruby-lang.org", "221.186.184.68"] p sock.peeraddr(true) #=> ["AF_INET", 80, "carbon.ruby-lang.org", "221.186.184.68"] p sock.peeraddr(false) #=> ["AF_INET", 80, "221.186.184.68", "221.186.184.68"] p sock.peeraddr(:hostname) #=> ["AF_INET", 80, "carbon.ruby-lang.org", "221.186.184.68"] p sock.peeraddr(:numeric) #=> ["AF_INET", 80, "221.186.184.68", "221.186.184.68"] }
Lookups the IP address of host.
require 'socket' IPSocket.getaddress("localhost") #=> "127.0.0.1" IPSocket.getaddress("ip6-localhost") #=> "::1"
returns a list of addrinfo objects as an array.
This method converts nodename (hostname) and service (port) to addrinfo. Since the conversion is not unique, the result is a list of addrinfo objects.
nodename or service can be nil if no conversion intended.
family, socktype and protocol are hint for preferred protocol. If the result will be used for a socket with SOCK_STREAM, SOCK_STREAM should be specified as socktype. If so, Addrinfo.getaddrinfo returns addrinfo list appropriate for SOCK_STREAM. If they are omitted or nil is given, the result is not restricted.
Similarly, PF_INET6 as family restricts for IPv6.
flags should be bitwise OR of Socket::AI_??? constants such as follows. Note that the exact list of the constants depends on OS.
AI_PASSIVE Get address to use with bind() AI_CANONNAME Fill in the canonical name AI_NUMERICHOST Prevent host name resolution AI_NUMERICSERV Prevent service name resolution AI_V4MAPPED Accept IPv4-mapped IPv6 addresses AI_ALL Allow all addresses AI_ADDRCONFIG Accept only if any address is assigned
Note that socktype should be specified whenever application knows the usage of the address. Some platform causes an error when socktype is omitted and servname is specified as an integer because some port numbers, 512 for example, are ambiguous without socktype.
Addrinfo.getaddrinfo("www.kame.net", 80, nil, :STREAM) #=> [#<Addrinfo: 203.178.141.194:80 TCP (www.kame.net)>, # #<Addrinfo: [2001:200:dff:fff1:216:3eff:feb1:44d7]:80 TCP (www.kame.net)>]
returns nodename and service as a pair of strings. This converts struct sockaddr in addrinfo to textual representation.
flags should be bitwise OR of Socket::NI_??? constants.
Addrinfo.tcp("127.0.0.1", 80).getnameinfo #=> ["localhost", "www"] Addrinfo.tcp("127.0.0.1", 80).getnameinfo(Socket::NI_NUMERICSERV) #=> ["localhost", "80"]
Closes the SOCKS connection.
Use Addrinfo.getaddrinfo instead. This method is deprecated for the following reasons:
The 3rd element of the result is the address family of the first address. The address families of the rest of the addresses are not returned.
gethostbyname() may take a long time and it may block other threads. (GVL cannot be released since gethostbyname() is not thread safe.)
This method uses gethostbyname() function already removed from POSIX.
This method lookups host information by hostname.
TCPSocket.gethostbyname("localhost") #=> ["localhost", ["hal"], 2, "127.0.0.1"]
Returns the remote address as an array which contains address_family and unix_path.
Example
serv = UNIXServer.new("/tmp/sock") c = UNIXSocket.new("/tmp/sock") p c.peeraddr #=> ["AF_UNIX", "/tmp/sock"]
Closes self for both reading and writing.
Raises IOError if reading or writing is attempted.
Related: StringIO#close_read, StringIO#close_write.
Returns true if self is closed for both reading and writing, false otherwise.
Reads and returns the next character from the stream; see Character IO.
Pushes back (“unshifts”) a character or integer onto the stream; see Character IO.
Pushes back (“unshifts”) an 8-bit byte onto the stream; see Byte IO.
Reads and returns the next 8-bit byte from the stream; see Byte IO.
Reads and returns a line from the stream; assigns the return value to $_; see Line IO.
Sets the scan pointer to the end of the string and clear matching data.
Returns the byte position of the scan pointer. In the ‘reset’ position, this value is zero. In the ‘terminated’ position (i.e. the string is exhausted), this value is the bytesize of the string.
In short, it’s a 0-based index into bytes of the string.
s = StringScanner.new('test string') s.pos # -> 0 s.scan_until /str/ # -> "test str" s.pos # -> 8 s.terminate # -> #<StringScanner fin> s.pos # -> 11
Sets the byte position of the scan pointer.
s = StringScanner.new('test string') s.pos = 7 # -> 7 s.rest # -> "ring"
Scans one character and returns it. This method is multibyte character sensitive.
s = StringScanner.new("ab") s.getch # => "a" s.getch # => "b" s.getch # => nil s = StringScanner.new("\244\242".force_encoding("euc-jp")) s.getch # => "\x{A4A2}" # Japanese hira-kana "A" in EUC-JP s.getch # => nil