Returns true
if the class was initialized with keyword_init: true
. Otherwise returns nil
or false
.
Examples:
Foo = Struct.new(:a) Foo.keyword_init? # => nil Bar = Struct.new(:a, keyword_init: true) Bar.keyword_init? # => true Baz = Struct.new(:a, keyword_init: false) Baz.keyword_init? # => false
Returns a hash of the name/value pairs for the given member names.
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) h = joe.deconstruct_keys([:zip, :address]) h # => {:zip=>12345, :address=>"123 Maple, Anytown NC"}
Returns all names and values if array_of_names
is nil
:
h = joe.deconstruct_keys(nil) h # => {:name=>"Joseph Smith, Jr.", :address=>"123 Maple, Anytown NC", :zip=>12345}
Returns a JSON
string representing self
:
require 'json/add/symbol' puts :foo.to_json
Output:
# {"json_class":"Symbol","s":"foo"}
Returns a Proc
object which calls the method with name of self
on the first parameter and passes the remaining parameters to the method.
proc = :to_s.to_proc # => #<Proc:0x000001afe0e48680(&:to_s) (lambda)> proc.call(1000) # => "1000" proc.call(1000, 16) # => "3e8" (1..3).collect(&:to_s) # => ["1", "2", "3"]
Equivalent to self.to_s.start_with?
; see String#start_with?
.
Returns true if this class can be used to create an instance from a serialised JSON
string. The class has to implement a class method json_create that expects a hash as first parameter. The hash should include the required data.
Return the path as a String
.
to_path
is implemented so Pathname
objects are usable with File.open
, etc.
This method is called when the parser found syntax error.
Receives up to maxlen bytes from socket
using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. flags is zero or more of the MSG_
options. The first element of the results, mesg, is the data received. The second element, sender_addrinfo, contains protocol-specific address information of the sender.
When recvfrom(2) returns 0, Socket#recv_nonblock
returns nil. In most cases it means the connection was closed, but for UDP connections it may mean an empty packet was received, as the underlying API makes it impossible to distinguish these two cases.
maxlen
- the maximum number of bytes to receive from the socket
flags
- zero or more of the MSG_
options
outbuf
- destination String
buffer
opts
- keyword hash, supporting ‘exception: false`
# In one file, start this first require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.bind(sockaddr) socket.listen(5) client, client_addrinfo = socket.accept begin # emulate blocking recvfrom pair = client.recvfrom_nonblock(20) rescue IO::WaitReadable IO.select([client]) retry end data = pair[0].chomp puts "I only received 20 bytes '#{data}'" sleep 1 socket.close # In another file, start this second require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.connect(sockaddr) socket.puts "Watch this get cut short!" socket.close
Refer to Socket#recvfrom
for the exceptions that may be thrown if the call to recvfrom_nonblock fails.
Socket#recvfrom_nonblock
may raise any error corresponding to recvfrom(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying recvfrom_nonblock.
By specifying a keyword argument exception to false
, you can indicate that recvfrom_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
Returns a socket object which contains the file descriptor, fd.
# If invoked by inetd, STDIN/STDOUT/STDERR is a socket. STDIN_SOCK = Socket.for_fd(STDIN.fileno) p STDIN_SOCK.remote_address
Disallows further read using shutdown system call.
s1, s2 = UNIXSocket.pair s1.close_read s2.puts #=> Broken pipe (Errno::EPIPE)
Returns an Addrinfo
object for local address obtained by getsockname.
Note that addrinfo.protocol is filled by 0.
TCPSocket.open("www.ruby-lang.org", 80) {|s| p s.local_address #=> #<Addrinfo: 192.168.0.129:36873 TCP> } TCPServer.open("127.0.0.1", 1512) {|serv| p serv.local_address #=> #<Addrinfo: 127.0.0.1:1512 TCP> }
Returns an address of the socket suitable for connect in the local machine.
This method returns self.local_address, except following condition.
IPv4 unspecified address (0.0.0.0) is replaced by IPv4 loopback address (127.0.0.1).
IPv6 unspecified address (::) is replaced by IPv6 loopback address (::1).
If the local address is not suitable for connect, SocketError
is raised. IPv4 and IPv6 address which port is 0 is not suitable for connect. Unix domain socket which has no path is not suitable for connect.
Addrinfo.tcp("0.0.0.0", 0).listen {|serv| p serv.connect_address #=> #<Addrinfo: 127.0.0.1:53660 TCP> serv.connect_address.connect {|c| s, _ = serv.accept p [c, s] #=> [#<Socket:fd 4>, #<Socket:fd 6>] } }
Receives up to maxlen bytes from socket
using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. flags is zero or more of the MSG_
options. The result, mesg, is the data received.
When recvfrom(2) returns 0, Socket#recv_nonblock
returns nil. In most cases it means the connection was closed, but for UDP connections it may mean an empty packet was received, as the underlying API makes it impossible to distinguish these two cases.
maxlen
- the number of bytes to receive from the socket
flags
- zero or more of the MSG_
options
buf
- destination String
buffer
options
- keyword hash, supporting ‘exception: false`
serv = TCPServer.new("127.0.0.1", 0) af, port, host, addr = serv.addr c = TCPSocket.new(addr, port) s = serv.accept c.send "aaa", 0 begin # emulate blocking recv. p s.recv_nonblock(10) #=> "aaa" rescue IO::WaitReadable IO.select([s]) retry end
Refer to Socket#recvfrom
for the exceptions that may be thrown if the call to recv_nonblock fails.
BasicSocket#recv_nonblock
may raise any error corresponding to recvfrom(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying recv_nonblock.
By specifying a keyword argument exception to false
, you can indicate that recv_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
recvmsg receives a message using recvmsg(2) system call in non-blocking manner.
It is similar to BasicSocket#recvmsg
but non-blocking flag is set before the system call and it doesn’t retry the system call.
By specifying a keyword argument exception to false
, you can indicate that recvmsg_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
creates a socket connected to remote_addr_args and bound to self.
The optional last argument opts is options represented by a hash. opts may have following options:
specify the timeout in seconds.
If a block is given, it is called with the socket and the value of the block is returned. The socket is returned otherwise.
Addrinfo.tcp("0.0.0.0", 4649).connect_to("www.ruby-lang.org", 80) {|s| s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" puts s.read }
Returns the IP address as a string.
Addrinfo.tcp("127.0.0.1", 80).ip_address #=> "127.0.0.1" Addrinfo.tcp("::1", 80).ip_address #=> "::1"
Returns the port number as an integer.
Addrinfo.tcp("127.0.0.1", 80).ip_port #=> 80 Addrinfo.tcp("::1", 80).ip_port #=> 80
Returns true for IPv4 multicast address (224.0.0.0/4). It returns false otherwise.