Copies from the given src to the given dst, returning the number of bytes copied.
The given src must be one of the following:
The path to a readable file, from which source data is to be read.
An IO-like object, opened for reading and capable of responding to method :readpartial or method :read.
The given dst must be one of the following:
The path to a writable file, to which data is to be written.
An IO-like object, opened for writing and capable of responding to method :write.
The examples here use file t.txt as source:
File.read('t.txt') # => "First line\nSecond line\n\nThird line\nFourth line\n" File.read('t.txt').size # => 47
If only arguments src and dst are given, the entire source stream is copied:
# Paths. IO.copy_stream('t.txt', 't.tmp') # => 47 # IOs (recall that a File is also an IO). src_io = File.open('t.txt', 'r') # => #<File:t.txt> dst_io = File.open('t.tmp', 'w') # => #<File:t.tmp> IO.copy_stream(src_io, dst_io) # => 47 src_io.close dst_io.close
With argument src_length a non-negative integer, no more than that many bytes are copied:
IO.copy_stream('t.txt', 't.tmp', 10) # => 10 File.read('t.tmp') # => "First line"
With argument src_offset also given, the source stream is read beginning at that offset:
IO.copy_stream('t.txt', 't.tmp', 11, 11) # => 11 IO.read('t.tmp') # => "Second line"
Returns the Encoding object that represents the encoding of the stream, or nil if the stream is in write mode and no encoding is specified.
See Encodings.
Returns the Encoding object that represents the encoding of the internal string, if conversion is specified, or nil otherwise.
See Encodings.
Yields all attributes (as symbols) along with the corresponding values or returns an enumerator if no block is given.
require "ostruct" data = OpenStruct.new("country" => "Australia", :capital => "Canberra") data.each_pair.to_a # => [[:country, "Australia"], [:capital, "Canberra"]]
Deserializes JSON string by constructing new Regexp object with source s (Regexp or String) and options o serialized by to_json
With no argument, returns the value of $!, which is the result of the most recent pattern match (see Regexp Global Variables):
/c(.)t/ =~ 'cat' # => 0 Regexp.last_match # => #<MatchData "cat" 1:"a"> /a/ =~ 'foo' # => nil Regexp.last_match # => nil
With non-negative integer argument n, returns the _n_th field in the matchdata, if any, or nil if none:
/c(.)t/ =~ 'cat' # => 0 Regexp.last_match(0) # => "cat" Regexp.last_match(1) # => "a" Regexp.last_match(2) # => nil
With negative integer argument n, counts backwards from the last field:
Regexp.last_match(-1) # => "a"
With string or symbol argument name, returns the string value for the named capture, if any:
/(?<lhs>\w+)\s*=\s*(?<rhs>\w+)/ =~ 'var = val' Regexp.last_match # => #<MatchData "var = val" lhs:"var"rhs:"val"> Regexp.last_match(:lhs) # => "var" Regexp.last_match('rhs') # => "val" Regexp.last_match('foo') # Raises IndexError.
Returns true if matching against re can be done in linear time to the input string.
Regexp.linear_time?(/re/) # => true
Note that this is a property of the ruby interpreter, not of the argument regular expression. Identical regexp can or cannot run in linear time depending on your ruby binary. Neither forward nor backward compatibility is guaranteed about the return value of this method. Our current algorithm is (*1) but this is subject to change in the future. Alternative implementations can also behave differently. They might always return false for everything.
Calls the given block with each member name/value pair; returns self:
Customer = Struct.new(:name, :address, :zip) # => Customer joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.each_pair {|(name, value)| p "#{name} => #{value}" }
Output:
"name => Joe Smith" "address => 123 Maple, Anytown NC" "zip => 12345"
Returns an Enumerator if no block is given.
Related: each.
Returns an array of values from self.
With integer arguments integers given, returns an array containing each value given by one of integers:
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.values_at(0, 2) # => ["Joe Smith", 12345] joe.values_at(2, 0) # => [12345, "Joe Smith"] joe.values_at(2, 1, 0) # => [12345, "123 Maple, Anytown NC", "Joe Smith"] joe.values_at(0, -3) # => ["Joe Smith", "Joe Smith"]
Raises IndexError if any of integers is out of range; see Array Indexes at Array.
With integer range argument integer_range given, returns an array containing each value given by the elements of the range; fills with nil values for range elements larger than the structure:
joe.values_at(0..2) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(-3..-1) # => ["Joe Smith", "123 Maple, Anytown NC", 12345] joe.values_at(1..4) # => ["123 Maple, Anytown NC", 12345, nil, nil]
Raises RangeError if any element of the range is negative and out of range; see Array Indexes at Array.
Equivalent to self.to_s.start_with?; see String#start_with?.
Equivalent to self.to_s.end_with?; see String#end_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.
Returns the object for which the receiver is the singleton class.
Raises an TypeError if the class is not a singleton class.
class Foo; end Foo.singleton_class.attached_object #=> Foo Foo.attached_object #=> TypeError: `Foo' is not a singleton class Foo.new.singleton_class.attached_object #=> #<Foo:0x000000010491a370> TrueClass.attached_object #=> TypeError: `TrueClass' is not a singleton class NilClass.attached_object #=> TypeError: `NilClass' is not a singleton class
creates an Addrinfo object from the arguments.
The arguments are interpreted as similar to self.
Addrinfo.tcp("0.0.0.0", 4649).family_addrinfo("www.ruby-lang.org", 80) #=> #<Addrinfo: 221.186.184.68:80 TCP (www.ruby-lang.org:80)> Addrinfo.unix("/tmp/sock").family_addrinfo("/tmp/sock2") #=> #<Addrinfo: /tmp/sock2 SOCK_STREAM>
creates a new Socket connected to the address of local_addrinfo.
If local_addrinfo is nil, the address of the socket is not bound.
The timeout specify the seconds for timeout. Errno::ETIMEDOUT is raised when timeout occur.
If a block is given the created socket is yielded for each address.
Returns the IP address and port number as 2-element array.
Addrinfo.tcp("127.0.0.1", 80).ip_unpack #=> ["127.0.0.1", 80] Addrinfo.tcp("::1", 80).ip_unpack #=> ["::1", 80]
Returns true for IPv4 private address (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). It returns false otherwise.
Returns the Encoding object that represents the encoding of the file. If the stream is write mode and no encoding is specified, returns nil.
Returns the Encoding of the internal string if conversion is specified. Otherwise returns nil.