Defines an instance method in the receiver. The method parameter can be a Proc
, a Method
or an UnboundMethod
object. If a block is specified, it is used as the method body. If a block or the method parameter has parameters, they’re used as method parameters. This block is evaluated using instance_eval
.
class A def fred puts "In Fred" end def create_method(name, &block) self.class.define_method(name, &block) end define_method(:wilma) { puts "Charge it!" } define_method(:flint) {|name| puts "I'm #{name}!"} end class B < A define_method(:barney, instance_method(:fred)) end a = B.new a.barney a.wilma a.flint('Dino') a.create_method(:betty) { p self } a.betty
produces:
In Fred Charge it! I'm Dino! #<B:0x401b39e8>
Returns true
if the named method is defined by mod. If inherit is set, the lookup will also search mod’s ancestors. Public and protected methods are matched. String
arguments are converted to symbols.
module A def method1() end def protected_method1() end protected :protected_method1 end class B def method2() end def private_method2() end private :private_method2 end class C < B include A def method3() end end A.method_defined? :method1 #=> true C.method_defined? "method1" #=> true C.method_defined? "method2" #=> true C.method_defined? "method2", true #=> true C.method_defined? "method2", false #=> false C.method_defined? "method3" #=> true C.method_defined? "protected_method1" #=> true C.method_defined? "method4" #=> false C.method_defined? "private_method2" #=> false
Returns true
if the arguments define a valid ordinal date, false
otherwise:
Date.valid_ordinal?(2001, 34) # => true Date.valid_ordinal?(2001, 366) # => false
See argument start.
Related: Date.jd
, Date.ordinal
.
Erases the line at the cursor corresponding to mode
. mode
may be either: 0: after cursor 1: before and cursor 2: entire line
You must require ‘io/console’ to use this method.
Calls the block with each remaining line read from the stream; returns self
. Does nothing if already at end-of-stream; See Line IO.
With no arguments given, reads lines as determined by line separator $/
:
f = File.new('t.txt') f.each_line {|line| p line } f.each_line {|line| fail 'Cannot happen' } f.close
Output:
"First line\n" "Second line\n" "\n" "Fourth line\n" "Fifth line\n"
With only string argument sep
given, reads lines as determined by line separator sep
; see Line Separator:
f = File.new('t.txt') f.each_line('li') {|line| p line } f.close
Output:
"First li" "ne\nSecond li" "ne\n\nFourth li" "ne\nFifth li" "ne\n"
The two special values for sep
are honored:
f = File.new('t.txt') # Get all into one string. f.each_line(nil) {|line| p line } f.close
Output:
"First line\nSecond line\n\nFourth line\nFifth line\n" f.rewind # Get paragraphs (up to two line separators). f.each_line('') {|line| p line }
Output:
"First line\nSecond line\n\n" "Fourth line\nFifth line\n"
With only integer argument limit
given, limits the number of bytes in each line; see Line Limit:
f = File.new('t.txt') f.each_line(8) {|line| p line } f.close
Output:
"First li" "ne\n" "Second l" "ine\n" "\n" "Fourth l" "ine\n" "Fifth li" "ne\n"
With arguments sep
and limit
given, combines the two behaviors (see Line Separator and Line Limit).
Optional keyword argument chomp
specifies whether line separators are to be omitted:
f = File.new('t.txt') f.each_line(chomp: true) {|line| p line } f.close
Output:
"First line" "Second line" "" "Fourth line" "Fifth line"
Returns an Enumerator
if no block is given.
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.
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.
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.
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
Dup internal hash.
Clone internal hash.
Returns true
if the class was initialized with keyword_init: true
. Otherwise returns nil
or false
.
Examples:
Foo = Struct.new(:a) Foo.keyword_init? # => nil Bar = Struct.new(:a, keyword_init: true) Bar.keyword_init? # => true Baz = Struct.new(:a, keyword_init: false) Baz.keyword_init? # => false
Iterates over each line in the file and yields a String
object for each.
Packs port and host as an AF_INET/AF_INET6 sockaddr string.
Socket.sockaddr_in(80, "127.0.0.1") #=> "\x02\x00\x00P\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00" Socket.sockaddr_in(80, "::1") #=> "\n\x00\x00P\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00"
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 a string which shows the sockaddr in addrinfo with human-readable form.
Addrinfo.tcp("localhost", 80).inspect_sockaddr #=> "127.0.0.1:80" Addrinfo.tcp("ip6-localhost", 80).inspect_sockaddr #=> "[::1]:80" Addrinfo.unix("/tmp/sock").inspect_sockaddr #=> "/tmp/sock"
Returns true for IPv6 link local address (fe80::/10). It returns false otherwise.
Returns true for IPv4-mapped IPv6 address (::ffff:0:0/80). It returns false otherwise.
Calls the block with each remaining line read from the stream; does nothing if already at end-of-file; returns self
. See Line IO.
With a block given, calls the block with each remaining codepoint in the stream; see Codepoint IO.
With no block given, returns an enumerator.
Returns the Encoding
object that represents the encoding of the file. If the stream is write mode and no encoding is specified, returns nil
.
Specify the encoding of the StringIO
as ext_enc. Use the default external encoding if ext_enc is nil. 2nd argument int_enc and optional hash opt argument are ignored; they are for API compatibility to IO
.
Returns a shallow copy of self
; the [stored string] in the copy is the same string as in self
.