Receives up to maxlen bytes from udpsocket using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. If maxlen is omitted, its default value is 65536. flags is zero or more of the MSG_ options. The first element of the results, mesg, is the data received. The second element, sender_inet_addr, is an array to represent the sender address.
When recvfrom(2) returns 0, Socket#recvfrom_nonblock returns an empty string as data. It means an empty packet.
maxlen - the number of bytes to receive from the socket
flags - zero or more of the MSG_ options
outbuf - destination String buffer
options - keyword hash, supporting ‘exception: false`
require 'socket' s1 = UDPSocket.new s1.bind("127.0.0.1", 0) s2 = UDPSocket.new s2.bind("127.0.0.1", 0) s2.connect(*s1.addr.values_at(3,1)) s1.connect(*s2.addr.values_at(3,1)) s1.send "aaa", 0 begin # emulate blocking recvfrom p s2.recvfrom_nonblock(10) #=> ["aaa", ["AF_INET", 33302, "localhost.localdomain", "127.0.0.1"]] rescue IO::WaitReadable IO.select([s2]) retry end
Refer to Socket#recvfrom for the exceptions that may be thrown if the call to recvfrom_nonblock fails.
UDPSocket#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 ‘exception: false`, the options hash allows you to indicate that recvmsg_nonblock should not raise an IO::WaitWritable exception, but return the symbol :wait_writable instead.
Example
UNIXServer.open("/tmp/sock") {|serv| UNIXSocket.open("/tmp/sock") {|c| s = serv.accept c.send_io STDOUT stdout = s.recv_io p STDOUT.fileno #=> 1 p stdout.fileno #=> 7 stdout.puts "hello" # outputs "hello\n" to standard output. } }
klass will determine the class of io returned (using the IO.for_fd singleton method or similar). If klass is nil, an integer file descriptor is returned.
mode is the same as the argument passed to IO.for_fd
Closes the read end of a StringIO. Will raise an IOError if the strio is not readable.
Returns true if strio is not readable, false otherwise.
This method is defined for backward compatibility.
Return the pre-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Return the post-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Defines the constants of OLE Automation server as mod’s constants. The first argument is WIN32OLE object or type library name. If 2nd argument is omitted, the default is WIN32OLE. The first letter of Ruby’s constant variable name is upper case, so constant variable name of WIN32OLE object is capitalized. For example, the ‘xlTop’ constant of Excel is changed to ‘XlTop’ in WIN32OLE. If the first letter of constant variable is not [A-Z], then the constant is defined as CONSTANTS hash element.
module EXCEL_CONST end excel = WIN32OLE.new('Excel.Application') WIN32OLE.const_load(excel, EXCEL_CONST) puts EXCEL_CONST::XlTop # => -4160 puts EXCEL_CONST::CONSTANTS['_xlDialogChartSourceData'] # => 541 WIN32OLE.const_load(excel) puts WIN32OLE::XlTop # => -4160 module MSO end WIN32OLE.const_load('Microsoft Office 9.0 Object Library', MSO) puts MSO::MsoLineSingle # => 1
Invokes Release method of Dispatch interface of WIN32OLE object. You should not use this method because this method exists only for debugging WIN32OLE. The return value is reference counter of OLE object.
Creates GUID.
WIN32OLE.create_guid # => {1CB530F1-F6B1-404D-BCE6-1959BF91F4A8}
invokes Release method of Dispatch interface of WIN32OLE object. Usually, you do not need to call this method because Release method called automatically when WIN32OLE object garbaged.
Returns string of return value type of method.
tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbooks') method = WIN32OLE_METHOD.new(tobj, 'Add') puts method.return_type # => Workbook
Returns number of return value type of method.
tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbooks') method = WIN32OLE_METHOD.new(tobj, 'Add') puts method.return_vtype # => 26
Returns major version.
tobj = WIN32OLE_TYPE.new('Microsoft Word 10.0 Object Library', 'Documents') puts tobj.major_version # => 8
Returns minor version.
tobj = WIN32OLE_TYPE.new('Microsoft Word 10.0 Object Library', 'Documents') puts tobj.minor_version # => 2
Returns the type library major version.
tlib = WIN32OLE_TYPELIB.new('Microsoft Excel 9.0 Object Library') puts tlib.major_version # -> 1
Returns the type library minor version.
tlib = WIN32OLE_TYPELIB.new('Microsoft Excel 9.0 Object Library') puts tlib.minor_version # -> 3
Evaluates a string containing Ruby source code, or the given block, within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj’s instance variables and private methods.
When instance_eval is given a block, obj is also passed in as the block’s only argument.
When instance_eval is given a String, the optional second and third parameters supply a filename and starting line number that are used when reporting compilation errors.
class KlassWithSecret def initialize @secret = 99 end private def the_secret "Ssssh! The secret is #{@secret}." end end k = KlassWithSecret.new k.instance_eval { @secret } #=> 99 k.instance_eval { the_secret } #=> "Ssssh! The secret is 99." k.instance_eval {|obj| obj == self } #=> true
Executes the given block within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj’s instance variables. Arguments are passed as block parameters.
class KlassWithSecret def initialize @secret = 99 end end k = KlassWithSecret.new k.instance_exec(5) {|x| @secret+x } #=> 104
Returns self.
Creates a hash with a copy of the environment variables.
Returns true if headers will be returned as a row of results. See CSV::new for details.
Returns true if all output fields are quoted. See CSV::new for details.
This method is an encoding safe version of Regexp::escape(). It will escape any characters that would change the meaning of a regular expression in the encoding of str. Regular expression characters that cannot be transcoded to the target encoding will be skipped and no escaping will be performed if a backslash cannot be transcoded.