Returns the number of nanoseconds in the subseconds part of self in the range (0..999_999_999); lower-order digits are truncated, not rounded:
t = Time.now # => 2022-07-11 15:04:53.3219637 -0500 t.nsec # => 321963700
Related: Time#subsec (returns exact subseconds).
Set the cursor position at column in the same line of the current position.
You must require ‘io/console’ to use this method.
Calls the given block with each codepoint in the stream; returns self:
f = File.new('t.rus') a = [] f.each_codepoint {|c| a << c } a # => [1090, 1077, 1089, 1090] f.close
Returns an Enumerator if no block is given.
Related: IO#each_byte, IO#each_char.
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.
See Encodings.
Argument ext_enc, if given, must be an Encoding object or a String with the encoding name; it is assigned as the encoding for the stream.
Argument int_enc, if given, must be an Encoding object or a String with the encoding name; it is assigned as the encoding for the internal string.
Argument 'ext_enc:int_enc', if given, is a string containing two colon-separated encoding names; corresponding Encoding objects are assigned as the external and internal encodings for the stream.
If the external encoding of a string is binary/ASCII-8BIT, the internal encoding of the string is set to nil, since no transcoding is needed.
Optional keyword arguments enc_opts specify Encoding options.
Writes the given string to ios using the write(2) system call after O_NONBLOCK is set for the underlying file descriptor.
It returns the number of bytes written.
write_nonblock just calls the write(2) system call. It causes all errors the write(2) system call causes: Errno::EWOULDBLOCK, Errno::EINTR, etc. The result may also be smaller than string.length (partial write). The caller should care such errors and partial write.
If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN, it is extended by IO::WaitWritable. So IO::WaitWritable can be used to rescue the exceptions for retrying write_nonblock.
# Creates a pipe. r, w = IO.pipe # write_nonblock writes only 65536 bytes and return 65536. # (The pipe size is 65536 bytes on this environment.) s = "a" * 100000 p w.write_nonblock(s) #=> 65536 # write_nonblock cannot write a byte and raise EWOULDBLOCK (EAGAIN). p w.write_nonblock("b") # Resource temporarily unavailable (Errno::EAGAIN)
If the write buffer is not empty, it is flushed at first.
When write_nonblock raises an exception kind of IO::WaitWritable, write_nonblock should not be called until io is writable for avoiding busy loop. This can be done as follows.
begin result = io.write_nonblock(string) rescue IO::WaitWritable, Errno::EINTR IO.select(nil, [io]) retry end
Note that this doesn’t guarantee to write all data in string. The length written is reported as result and it should be checked later.
On some platforms such as Windows, write_nonblock is not supported according to the kind of the IO object. In such cases, write_nonblock raises Errno::EBADF.
By specifying a keyword argument exception to false, you can indicate that write_nonblock should not raise an IO::WaitWritable exception, but return the symbol :wait_writable instead.
Methods BigDecimal#as_json and BigDecimal.json_create may be used to serialize and deserialize a BigDecimal object; see Marshal.
Method BigDecimal#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/bigdecimal' x = BigDecimal(2).as_json # => {"json_class"=>"BigDecimal", "b"=>"27:0.2e1"} y = BigDecimal(2.0, 4).as_json # => {"json_class"=>"BigDecimal", "b"=>"36:0.2e1"} z = BigDecimal(Complex(2, 0)).as_json # => {"json_class"=>"BigDecimal", "b"=>"27:0.2e1"}
Method JSON.create deserializes such a hash, returning a BigDecimal object:
BigDecimal.json_create(x) # => 0.2e1 BigDecimal.json_create(y) # => 0.2e1 BigDecimal.json_create(z) # => 0.2e1
Returns a JSON string representing self:
require 'json/add/bigdecimal' puts BigDecimal(2).to_json puts BigDecimal(2.0, 4).to_json puts BigDecimal(Complex(2, 0)).to_json
Output:
{"json_class":"BigDecimal","b":"27:0.2e1"}
{"json_class":"BigDecimal","b":"36:0.2e1"}
{"json_class":"BigDecimal","b":"27:0.2e1"}
Methods OpenStruct#as_json and OpenStruct.json_create may be used to serialize and deserialize a OpenStruct object; see Marshal.
Method OpenStruct#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/ostruct' x = OpenStruct.new('name' => 'Rowdy', :age => nil).as_json # => {"json_class"=>"OpenStruct", "t"=>{:name=>'Rowdy', :age=>nil}}
Method JSON.create deserializes such a hash, returning a OpenStruct object:
OpenStruct.json_create(x) # => #<OpenStruct name='Rowdy', age=nil>
Returns a JSON string representing self:
require 'json/add/ostruct' puts OpenStruct.new('name' => 'Rowdy', :age => nil).to_json
Output:
{"json_class":"OpenStruct","t":{'name':'Rowdy',"age":null}}
Methods Range#as_json and Range.json_create may be used to serialize and deserialize a Range object; see Marshal.
Method Range#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/range' x = (1..4).as_json # => {"json_class"=>"Range", "a"=>[1, 4, false]} y = (1...4).as_json # => {"json_class"=>"Range", "a"=>[1, 4, true]} z = ('a'..'d').as_json # => {"json_class"=>"Range", "a"=>["a", "d", false]}
Method JSON.create deserializes such a hash, returning a Range object:
Range.json_create(x) # => 1..4 Range.json_create(y) # => 1...4 Range.json_create(z) # => "a".."d"
Returns a JSON string representing self:
require 'json/add/range' puts (1..4).to_json puts (1...4).to_json puts ('a'..'d').to_json
Output:
{"json_class":"Range","a":[1,4,false]}
{"json_class":"Range","a":[1,4,true]}
{"json_class":"Range","a":["a","d",false]}
Methods Rational#as_json and Rational.json_create may be used to serialize and deserialize a Rational object; see Marshal.
Method Rational#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/rational' x = Rational(2, 3).as_json # => {"json_class"=>"Rational", "n"=>2, "d"=>3}
Method JSON.create deserializes such a hash, returning a Rational object:
Rational.json_create(x) # => (2/3)
Returns a JSON string representing self:
require 'json/add/rational' puts Rational(2, 3).to_json
Output:
{"json_class":"Rational","n":2,"d":3}
Methods Regexp#as_json and Regexp.json_create may be used to serialize and deserialize a Regexp object; see Marshal.
Method Regexp#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/regexp' x = /foo/.as_json # => {"json_class"=>"Regexp", "o"=>0, "s"=>"foo"}
Method JSON.create deserializes such a hash, returning a Regexp object:
Regexp.json_create(x) # => /foo/
Returns a JSON string representing self:
require 'json/add/regexp' puts /foo/.to_json
Output:
{"json_class":"Regexp","o":0,"s":"foo"}
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 false if self is applicable to a string with any ASCII-compatible encoding; otherwise returns true:
r = /a/ # => /a/ r.fixed_encoding? # => false r.match?("\u{6666} a") # => true r.match?("\xa1\xa2 a".force_encoding("euc-jp")) # => true r.match?("abc".force_encoding("euc-jp")) # => true r = /a/u # => /a/ r.fixed_encoding? # => true r.match?("\u{6666} a") # => true r.match?("\xa1\xa2".force_encoding("euc-jp")) # Raises exception. r.match?("abc".force_encoding("euc-jp")) # => true r = /\u{6666}/ # => /\u{6666}/ r.fixed_encoding? # => true r.encoding # => #<Encoding:UTF-8> r.match?("\u{6666} a") # => true r.match?("\xa1\xa2".force_encoding("euc-jp")) # Raises exception. r.match?("abc".force_encoding("euc-jp")) # => false
Methods Set#as_json and Set.json_create may be used to serialize and deserialize a Set object; see Marshal.
Method Set#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/set' x = Set.new(%w/foo bar baz/).as_json # => {"json_class"=>"Set", "a"=>["foo", "bar", "baz"]}
Method JSON.create deserializes such a hash, returning a Set object:
Set.json_create(x) # => #<Set: {"foo", "bar", "baz"}>
Returns a JSON string representing self:
require 'json/add/set' puts Set.new(%w/foo bar baz/).to_json
Output:
{"json_class":"Set","a":["foo","bar","baz"]}
Clone internal hash.
Methods Struct#as_json and Struct.json_create may be used to serialize and deserialize a Struct object; see Marshal.
Method Struct#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/struct' Customer = Struct.new('Customer', :name, :address, :zip) x = Struct::Customer.new.as_json # => {"json_class"=>"Struct::Customer", "v"=>[nil, nil, nil]}
Method JSON.create deserializes such a hash, returning a Struct object:
Struct::Customer.json_create(x) # => #<struct Struct::Customer name=nil, address=nil, zip=nil>
Returns a JSON string representing self:
require 'json/add/struct' Customer = Struct.new('Customer', :name, :address, :zip) puts Struct::Customer.new.to_json
Output:
{"json_class":"Struct","t":{'name':'Rowdy',"age":null}}
Methods Symbol#as_json and Symbol.json_create may be used to serialize and deserialize a Symbol object; see Marshal.
Method Symbol#as_json serializes self, returning a 2-element hash representing self:
require 'json/add/symbol' x = :foo.as_json # => {"json_class"=>"Symbol", "s"=>"foo"}
Method JSON.create deserializes such a hash, returning a Symbol object:
Symbol.json_create(x) # => :foo