Reads and returns the next 1-character string from the stream; raises EOFError if already at end-of-stream. See Character IO.
f = File.open('t.txt') f.readchar # => "F" f.close f = File.open('t.rus') f.readchar.ord # => 1090 f.close
Repositions the stream to its beginning, setting both the position and the line number to zero; see Position and Line Number:
f = File.open('t.txt') f.tell # => 0 f.lineno # => 0 f.gets # => "First line\n" f.tell # => 12 f.lineno # => 1 f.rewind # => 0 f.tell # => 0 f.lineno # => 0 f.close
Note that this method cannot be used with streams such as pipes, ttys, and sockets.
Reads a line as with IO#gets, but raises EOFError if already at end-of-stream.
Optional keyword argument chomp specifies whether line separators are to be omitted.
Returns the numerator.
Rational(7).numerator #=> 7 Rational(7, 1).numerator #=> 7 Rational(9, -4).numerator #=> -9 Rational(-2, -10).numerator #=> 1
Returns true if rat is less than 0.
Returns a simpler approximation of the value if the optional argument eps is given (rat-|eps| <= result <= rat+|eps|), self otherwise.
r = Rational(5033165, 16777216) r.rationalize #=> (5033165/16777216) r.rationalize(Rational('0.01')) #=> (3/10) r.rationalize(Rational('0.1')) #=> (1/3)
Removes all elements and returns self.
set = Set[1, 'c', :s] #=> #<Set: {1, "c", :s}> set.clear #=> #<Set: {}> set #=> #<Set: {}>
Deletes every element that appears in the given enumerable object and returns self.
Parses the given Ruby program read from src. src must be a String or an IO or a object with a gets method.
This method is called when weak warning is produced by the parser. fmt and args is printf style.
This method is called when strong warning is produced by the parser. fmt and args is printf style.
Requests a connection to be made on the given remote_sockaddr. Returns 0 if successful, otherwise an exception is raised.
remote_sockaddr - the struct sockaddr contained in a string or Addrinfo object
# Pull down Google's web page require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 80, 'www.google.com' ) socket.connect( sockaddr ) socket.write( "GET / HTTP/1.0\r\n\r\n" ) results = socket.read
On unix-based systems the following system exceptions may be raised if the call to connect fails:
Errno::EACCES - search permission is denied for a component of the prefix path or write access to the socket is denied
Errno::EADDRINUSE - the sockaddr is already in use
Errno::EADDRNOTAVAIL - the specified sockaddr is not available from the local machine
Errno::EAFNOSUPPORT - the specified sockaddr is not a valid address for the address family of the specified socket
Errno::EALREADY - a connection is already in progress for the specified socket
Errno::EBADF - the socket is not a valid file descriptor
Errno::ECONNREFUSED - the target sockaddr was not listening for connections refused the connection request
Errno::ECONNRESET - the remote host reset the connection request
Errno::EFAULT - the sockaddr cannot be accessed
Errno::EHOSTUNREACH - the destination host cannot be reached (probably because the host is down or a remote router cannot reach it)
Errno::EINPROGRESS - the O_NONBLOCK is set for the socket and the connection cannot be immediately established; the connection will be established asynchronously
Errno::EINTR - the attempt to establish the connection was interrupted by delivery of a signal that was caught; the connection will be established asynchronously
Errno::EISCONN - the specified socket is already connected
Errno::EINVAL - the address length used for the sockaddr is not a valid length for the address family or there is an invalid family in sockaddr
Errno::ENAMETOOLONG - the pathname resolved had a length which exceeded PATH_MAX
Errno::ENETDOWN - the local interface used to reach the destination is down
Errno::ENETUNREACH - no route to the network is present
Errno::ENOBUFS - no buffer space is available
Errno::ENOSR - there were insufficient STREAMS resources available to complete the operation
Errno::ENOTSOCK - the socket argument does not refer to a socket
Errno::EOPNOTSUPP - the calling socket is listening and cannot be connected
Errno::EPROTOTYPE - the sockaddr has a different type than the socket bound to the specified peer address
Errno::ETIMEDOUT - the attempt to connect timed out before a connection was made.
On unix-based systems if the address family of the calling socket is AF_UNIX the follow exceptions may be raised if the call to connect fails:
Errno::EIO - an i/o error occurred while reading from or writing to the file system
Errno::ELOOP - too many symbolic links were encountered in translating the pathname in sockaddr
Errno::ENAMETOOLLONG - a component of a pathname exceeded NAME_MAX characters, or an entire pathname exceeded PATH_MAX characters
Errno::ENOENT - a component of the pathname does not name an existing file or the pathname is an empty string
Errno::ENOTDIR - a component of the path prefix of the pathname in sockaddr is not a directory
On Windows systems the following system exceptions may be raised if the call to connect fails:
Errno::ENETDOWN - the network is down
Errno::EADDRINUSE - the socket’s local address is already in use
Errno::EINTR - the socket was cancelled
Errno::EINPROGRESS - a blocking socket is in progress or the service provider is still processing a callback function. Or a nonblocking connect call is in progress on the socket.
Errno::EALREADY - see Errno::EINVAL
Errno::EADDRNOTAVAIL - the remote address is not a valid address, such as ADDR_ANY TODO check ADDRANY TO INADDR_ANY
Errno::EAFNOSUPPORT - addresses in the specified family cannot be used with with this socket
Errno::ECONNREFUSED - the target sockaddr was not listening for connections refused the connection request
Errno::EFAULT - the socket’s internal address or address length parameter is too small or is not a valid part of the user space address
Errno::EINVAL - the socket is a listening socket
Errno::EISCONN - the socket is already connected
Errno::ENETUNREACH - the network cannot be reached from this host at this time
Errno::EHOSTUNREACH - no route to the network is present
Errno::ENOBUFS - no buffer space is available
Errno::ENOTSOCK - the socket argument does not refer to a socket
Errno::ETIMEDOUT - the attempt to connect timed out before a connection was made.
Errno::EWOULDBLOCK - the socket is marked as nonblocking and the connection cannot be completed immediately
Errno::EACCES - the attempt to connect the datagram socket to the broadcast address failed
connect manual pages on unix-based systems
connect function in Microsoft’s Winsock functions reference
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"] }
creates a socket connected to the address of self.
The optional 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("www.ruby-lang.org", 80).connect {|s| s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" puts s.read }
Connects udpsocket to host:port.
This makes possible to send without destination address.
u1 = UDPSocket.new u1.bind("127.0.0.1", 4913) u2 = UDPSocket.new u2.connect("127.0.0.1", 4913) u2.send "uuuu", 0 p u1.recvfrom(10) #=> ["uuuu", ["AF_INET", 33230, "localhost", "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"]
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.