creates a listening socket bound to self.
returns a string which shows addrinfo in human-readable form.
Addrinfo.tcp("localhost", 80).inspect #=> "#<Addrinfo: 127.0.0.1:80 TCP (localhost)>" Addrinfo.unix("/tmp/sock").inspect #=> "#<Addrinfo: /tmp/sock SOCK_STREAM>"
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"]
Binds udpsocket to host:port.
u1 = UDPSocket.new u1.bind("127.0.0.1", 4913) u1.send "message-to-self", 0, "127.0.0.1", 4913 p u1.recvfrom(10) #=> ["message-to", ["AF_INET", 4913, "localhost", "127.0.0.1"]]
Listens for connections, using the specified int as the backlog. A call to listen only applies if the socket is of type SOCK_STREAM or SOCK_SEQPACKET.
backlog - the maximum length of the queue for pending connections.
require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.bind( sockaddr ) socket.listen( 5 )
require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) socket.listen( 1 )
On unix based systems the above will work because a new sockaddr struct is created on the address ADDR_ANY, for an arbitrary port number as handed off by the kernel. It will not work on Windows, because Windows requires that the socket is bound by calling bind before it can listen.
If the backlog amount exceeds the implementation-dependent maximum queue length, the implementation’s maximum queue length will be used.
On unix-based based systems the following system exceptions may be raised if the call to listen fails:
Errno::EBADF - the socket argument is not a valid file descriptor
Errno::EDESTADDRREQ - the socket is not bound to a local address, and the protocol does not support listening on an unbound socket
Errno::EINVAL - the socket is already connected
Errno::ENOTSOCK - the socket argument does not refer to a socket
Errno::EOPNOTSUPP - the socket protocol does not support listen
Errno::EACCES - the calling process does not have appropriate privileges
Errno::EINVAL - the socket has been shut down
Errno::ENOBUFS - insufficient resources are available in the system to complete the call
On Windows systems the following system exceptions may be raised if the call to listen fails:
Errno::ENETDOWN - the network is down
Errno::EADDRINUSE - the socket’s local address is already in use. This usually occurs during the execution of bind but could be delayed if the call to bind was to a partially wildcard address (involving ADDR_ANY) and if a specific address needs to be committed at the time of the call to listen
Errno::EINPROGRESS - a Windows Sockets 1.1 call is in progress or the service provider is still processing a callback function
Errno::EINVAL - the socket has not been bound with a call to bind.
Errno::EISCONN - the socket is already connected
Errno::EMFILE - no more socket descriptors are available
Errno::ENOBUFS - no buffer space is available
Errno::ENOTSOC - socket is not a socket
Errno::EOPNOTSUPP - the referenced socket is not a type that supports the listen method
listen manual pages on unix-based systems
listen function in Microsoft’s Winsock functions reference
Listens for connections, using the specified int as the backlog. A call to listen only applies if the socket is of type SOCK_STREAM or SOCK_SEQPACKET.
backlog - the maximum length of the queue for pending connections.
require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.bind( sockaddr ) socket.listen( 5 )
require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) socket.listen( 1 )
On unix based systems the above will work because a new sockaddr struct is created on the address ADDR_ANY, for an arbitrary port number as handed off by the kernel. It will not work on Windows, because Windows requires that the socket is bound by calling bind before it can listen.
If the backlog amount exceeds the implementation-dependent maximum queue length, the implementation’s maximum queue length will be used.
On unix-based based systems the following system exceptions may be raised if the call to listen fails:
Errno::EBADF - the socket argument is not a valid file descriptor
Errno::EDESTADDRREQ - the socket is not bound to a local address, and the protocol does not support listening on an unbound socket
Errno::EINVAL - the socket is already connected
Errno::ENOTSOCK - the socket argument does not refer to a socket
Errno::EOPNOTSUPP - the socket protocol does not support listen
Errno::EACCES - the calling process does not have appropriate privileges
Errno::EINVAL - the socket has been shut down
Errno::ENOBUFS - insufficient resources are available in the system to complete the call
On Windows systems the following system exceptions may be raised if the call to listen fails:
Errno::ENETDOWN - the network is down
Errno::EADDRINUSE - the socket’s local address is already in use. This usually occurs during the execution of bind but could be delayed if the call to bind was to a partially wildcard address (involving ADDR_ANY) and if a specific address needs to be committed at the time of the call to listen
Errno::EINPROGRESS - a Windows Sockets 1.1 call is in progress or the service provider is still processing a callback function
Errno::EINVAL - the socket has not been bound with a call to bind.
Errno::EISCONN - the socket is already connected
Errno::EMFILE - no more socket descriptors are available
Errno::ENOBUFS - no buffer space is available
Errno::ENOTSOC - socket is not a socket
Errno::EOPNOTSUPP - the referenced socket is not a type that supports the listen method
listen manual pages on unix-based systems
listen function in Microsoft’s Winsock functions reference
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 current line number in self; see Line Number.
Sets the current line number in self to the given new_line_number; see Line Number.
Sets the data mode in self to binary mode; see Data Mode.
Sets the current position and line number to zero; see Position and Line Number.
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.
Appends the given string to the underlying buffer string. The stream must be opened for writing. If the argument is not a string, it will be converted to a string using to_s. Returns the number of bytes written. See IO#write.
Returns the size of the buffer string.
Truncates the buffer string to at most integer bytes. The stream must be opened for writing.
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"
Looks ahead to see if the pattern exists anywhere in the string, without advancing the scan pointer. This predicates whether a scan_until will return a value.
s = StringScanner.new('test string') s.exist? /s/ # -> 3 s.scan /test/ # -> "test" s.exist? /s/ # -> 2 s.exist? /e/ # -> nil
Returns true if and only if there is more data in the string. See eos?. This method is obsolete; use eos? instead.
s = StringScanner.new('test string') s.eos? # These two s.rest? # are opposites.
Returns the “rest” of the string (i.e. everything after the scan pointer). If there is no more data (eos? = true), it returns "".
s.restsize is equivalent to s.rest_size. This method is obsolete; use rest_size instead.
Returns a string that represents the StringScanner object, showing:
the current position
the size of the string
the characters surrounding the scan pointer
s = StringScanner.new(“Fri Dec 12 1975 14:39”) s.inspect # -> ‘#<StringScanner 0/21 @ “Fri D…”>’ s.scan_until /12/ # -> “Fri Dec 12” s.inspect # -> ‘#<StringScanner 10/21 “…ec 12” @ “ 1975…”>’