Results for: "pstore"

Addrinfo#ipv6_multicast?

Returns true for IPv6 multicast address (ff00::/8). It returns false otherwise.

Addrinfo#to_sockaddr

returns the socket address as packed struct sockaddr string.

Addrinfo.tcp("localhost", 80).to_sockaddr
#=> "\x02\x00\x00P\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00"

Receives up to maxlen bytes from udpsocket 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_inet_addr, is an array to represent the sender address.

When recvfrom(2) returns 0, Socket#recv_nonblock returns nil. In most cases it means the connection was closed, but it may also mean an empty packet was received, as the underlying API makes it impossible to distinguish these two cases.

Parameters

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`

Example

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 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.

See

Socket#recvfrom

UNIXSocket#recv_io

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

StringIO#close_read

Closes self for reading; closed-write setting remains unchanged.

Raises IOError if reading is attempted.

StringIO#closed_read?

Returns true if self is closed for reading, false otherwise.

StringScanner#pre_match

Returns the substring that precedes the matched substring from the most recent match attempt if it was successful, or nil otherwise; see [Basic Match Values]:

scanner = StringScanner.new('foobarbaz')
scanner.pre_match      # => nil

scanner.pos = 3
scanner.exist?(/baz/)  # => 6
scanner.pre_match      # => "foobar" # Substring of entire string, not just target string.

scanner.exist?(/nope/) # => nil
scanner.pre_match      # => nil

StringScanner#post_match

Returns the substring that follows the matched substring from the most recent match attempt if it was successful, or nil otherwise; see [Basic Match Values]:

scanner = StringScanner.new('foobarbaz')
scanner.post_match     # => nil

scanner.pos = 3
scanner.match?(/bar/)  # => 3
scanner.post_match     # => "baz"

scanner.match?(/nope/) # => nil
scanner.post_match     # => nil

StringScanner#fixed_anchor?

Returns whether the [fixed-anchor property] is set.

StringScanner#named_captures

Returns the array of captured match values at indexes (1..) if the most recent match attempt succeeded, or nil otherwise; see [Captured Match Values]:

scanner = StringScanner.new('Fri Dec 12 1975 14:39')
scanner.named_captures # => {}

pattern = /(?<wday>\w+) (?<month>\w+) (?<day>\d+) /
scanner.match?(pattern)
scanner.named_captures # => {"wday"=>"Fri", "month"=>"Dec", "day"=>"12"}

scanner.string = 'nope'
scanner.match?(pattern)
scanner.named_captures # => {"wday"=>nil, "month"=>nil, "day"=>nil}

scanner.match?(/nosuch/)
scanner.named_captures # => {}

WIN32OLE::const_load

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

WIN32OLE::ole_free

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.

WIN32OLE::create_guid

Creates GUID.

WIN32OLE.create_guid # => {1CB530F1-F6B1-404D-BCE6-1959BF91F4A8}

WIN32OLE#ole_free

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.

BasicObject#instance_eval

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

BasicObject#instance_exec

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

Hash#to_hash

Returns self.

Hash#to_proc

Returns a Proc object that maps a key to its value:

h = {foo: 0, bar: 1, baz: 2}
proc = h.to_proc
proc.class # => Proc
proc.call(:foo) # => 0
proc.call(:bar) # => 1
proc.call(:nosuch) # => nil

Hash#transform_keys

Returns a new Hash object; each entry has:

A key provided by the block.
The value from self.

An optional hash argument can be provided to map keys to new keys. Any key not given will be mapped using the provided block, or remain the same if no block is given.

Transform keys:

h = {foo: 0, bar: 1, baz: 2}
h1 = h.transform_keys {|key| key.to_s }
h1 # => {"foo"=>0, "bar"=>1, "baz"=>2}

h.transform_keys(foo: :bar, bar: :foo)
#=> {bar: 0, foo: 1, baz: 2}

h.transform_keys(foo: :hello, &:to_s)
#=> {:hello=>0, "bar"=>1, "baz"=>2}

Overwrites values for duplicate keys:

h = {foo: 0, bar: 1, baz: 2}
h1 = h.transform_keys {|key| :bat }
h1 # => {:bat=>2}

Returns a new Enumerator if no block given:

h = {foo: 0, bar: 1, baz: 2}
e = h.transform_keys # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:transform_keys>
h1 = e.each { |key| key.to_s }
h1 # => {"foo"=>0, "bar"=>1, "baz"=>2}

Hash#transform_keys!

Same as Hash#transform_keys but modifies the receiver in place instead of returning a new hash.

Hash#transform_values

Returns a new Hash object; each entry has:

A key from self.
A value provided by the block.

Transform values:

h = {foo: 0, bar: 1, baz: 2}
h1 = h.transform_values {|value| value * 100}
h1 # => {:foo=>0, :bar=>100, :baz=>200}

Returns a new Enumerator if no block given:

h = {foo: 0, bar: 1, baz: 2}
e = h.transform_values # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:transform_values>
h1 = e.each { |value| value * 100}
h1 # => {:foo=>0, :bar=>100, :baz=>200}

Hash#transform_values!

Returns self, whose keys are unchanged, and whose values are determined by the given block.

h = {foo: 0, bar: 1, baz: 2}
h.transform_values! {|value| value * 100} # => {:foo=>0, :bar=>100, :baz=>200}

Returns a new Enumerator if no block given:

h = {foo: 0, bar: 1, baz: 2}
e = h.transform_values! # => #<Enumerator: {:foo=>0, :bar=>100, :baz=>200}:transform_values!>
h1 = e.each {|value| value * 100}
h1 # => {:foo=>0, :bar=>100, :baz=>200}

ENV::to_hash

Returns a Hash containing all name/value pairs from ENV:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.to_hash # => {"bar"=>"1", "foo"=>"0"}

ARGF#to_io

Returns an IO object representing the current file. This will be a File object unless the current file is a stream such as STDIN.

For example:

ARGF.to_io    #=> #<File:glark.txt>
ARGF.to_io    #=> #<IO:<STDIN>>

ARGF#read_nonblock

Reads at most maxlen bytes from the ARGF stream in non-blocking mode.