Results for: "partition"

Sets the console mode to mode.

You must require ‘io/console’ to use this method.

Scrolls the entire scrolls forward n lines.

You must require ‘io/console’ to use this method.

Scrolls the entire scrolls backward n lines.

You must require ‘io/console’ to use this method.

Clears the entire screen and moves the cursor top-left corner.

You must require ‘io/console’ to use this method.

Waits until IO is readable and returns a truthy value, or a falsy value when times out. Returns a truthy value immediately when buffered data is available.

You must require ‘io/wait’ to use this method.

Calls the given block with each character in the stream; returns self. See Character IO.

f = File.new('t.rus')
a = []
f.each_char {|c| a << c.ord }
a # => [1090, 1077, 1089, 1090]
f.close

Returns an Enumerator if no block is given.

Related: IO#each_byte, IO#each_codepoint.

Returns self.

Closes the stream for writing if open for writing; returns nil. See Open and Closed Streams.

Flushes any buffered writes to the operating system before closing.

If the stream was opened by IO.popen and is also closed for reading, sets global variable $? (child exit status).

IO.popen('ruby', 'r+') do |pipe|
  puts pipe.closed?
  pipe.close_read
  puts pipe.closed?
  pipe.close_write
  puts $?
  puts pipe.closed?
end

Output:

false
false
pid 15044 exit 0
true

Related: IO#close, IO#close_read, IO#closed?.

Returns the path associated with the IO, or nil if there is no path associated with the IO. It is not guaranteed that the path exists on the filesystem.

$stdin.path # => "<STDIN>"

File.open("testfile") {|f| f.path} # => "testfile"

Reads at most maxlen bytes from ios using the read(2) system call after O_NONBLOCK is set for the underlying file descriptor.

If the optional outbuf argument is present, it must reference a String, which will receive the data. The outbuf will contain only the received data after the method call even if it is not empty at the beginning.

read_nonblock just calls the read(2) system call. It causes all errors the read(2) system call causes: Errno::EWOULDBLOCK, Errno::EINTR, etc. The caller should care such errors.

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 read_nonblock.

read_nonblock causes EOFError on EOF.

On some platforms, such as Windows, non-blocking mode is not supported on IO objects other than sockets. In such cases, Errno::EBADF will be raised.

If the read byte buffer is not empty, read_nonblock reads from the buffer like readpartial. In this case, the read(2) system call is not called.

When read_nonblock raises an exception kind of IO::WaitReadable, read_nonblock should not be called until io is readable for avoiding busy loop. This can be done as follows.

# emulates blocking read (readpartial).
begin
  result = io.read_nonblock(maxlen)
rescue IO::WaitReadable
  IO.select([io])
  retry
end

Although IO#read_nonblock doesn’t raise IO::WaitWritable. OpenSSL::Buffering#read_nonblock can raise IO::WaitWritable. If IO and SSL should be used polymorphically, IO::WaitWritable should be rescued too. See the document of OpenSSL::Buffering#read_nonblock for sample code.

Note that this method is identical to readpartial except the non-blocking flag is set.

By specifying a keyword argument exception to false, you can indicate that read_nonblock should not raise an IO::WaitReadable exception, but return the symbol :wait_readable instead. At EOF, it will return nil instead of raising EOFError.

See as_json.

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"}

See as_json.

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}}

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"]]

See as_json.

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]}

See as_json.

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}

See as_json.

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/