Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking fibers (created by Fiber.new with blocking: false, or by Fiber.schedule) call that scheduler’s hook methods on potentially blocking operations, and the current thread will call scheduler’s close method on finalization (allowing the scheduler to properly manage all non-finished fibers).
scheduler can be an object of any class corresponding to Fiber::Scheduler. Its implementation is up to the user.
See also the “Non-blocking fibers” section in class docs.
Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler if and only if the current fiber is non-blocking.
Returns the locale charmap name. It returns nil if no appropriate information.
Debian GNU/Linux LANG=C Encoding.locale_charmap #=> "ANSI_X3.4-1968" LANG=ja_JP.EUC-JP Encoding.locale_charmap #=> "EUC-JP" SunOS 5 LANG=C Encoding.locale_charmap #=> "646" LANG=ja Encoding.locale_charmap #=> "eucJP"
The result is highly platform dependent. So Encoding.find(Encoding.locale_charmap) may cause an error. If you need some encoding object even for unknown locale, Encoding.find(“locale”) can be used.
Return the accept character set for all new CGI instances.
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:
Calls with the next line as determined by line separator sep.
But returns no more bytes than are allowed by the 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 byte (0..255) in the stream; returns self. See Byte IO.
f = File.new('t.rus') a = [] f.each_byte {|b| a << b } a # => [209, 130, 208, 181, 209, 129, 209, 130] f.close
Returns an Enumerator if no block is given.
Related: IO#each_char, IO#each_codepoint.
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.
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"]]
With a block given, passes each element of self to the block in reverse order:
a = [] (1..4).reverse_each {|element| a.push(element) } # => 1..4 a # => [4, 3, 2, 1] a = [] (1...4).reverse_each {|element| a.push(element) } # => 1...4 a # => [3, 2, 1]
With no block given, returns an enumerator.
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.
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 all symbols currently in Ruby’s symbol table:
Symbol.all_symbols.size # => 9334 Symbol.all_symbols.take(3) # => [:!, :"\"", :"#"]
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
Iterates over each component of the path.
Pathname.new("/usr/bin/ruby").each_filename {|filename| ... }
# yields "usr", "bin", and "ruby".
Returns an Enumerator if no block was given.
enum = Pathname.new("/usr/bin/ruby").each_filename
# ... do stuff ...
enum.each { |e| ... }
# yields "usr", "bin", and "ruby".
Iterates over each line in the file and yields a String object for each.
Iterates over the entries (files and subdirectories) in the directory, yielding a Pathname object for each entry.
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 byte in the stream; see Byte IO.
With no block given, returns an enumerator.
With a block given, calls the block with each remaining codepoint in the stream; see Codepoint IO.
With no block given, returns an enumerator.
This returns the value that scan_until would return, without advancing the scan pointer. The match register is affected, though.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.check_until /12/ # -> "Fri Dec 12" s.pos # -> 0 s.matched # -> 12
Mnemonic: it “checks” to see whether a scan_until will return a value.
Scans the string until the pattern is matched. Advances the scan pointer if advance_pointer_p, otherwise not. Returns the matched string if return_string_p is true, otherwise returns the number of bytes advanced. This method does affect the match register.
Returns the size of the most recent match in bytes, or nil if there was no recent match. This is different than matched.size, which will return the size in characters.
s = StringScanner.new('test string') s.check /\w+/ # -> "test" s.matched_size # -> 4 s.check /\d+/ # -> nil s.matched_size # -> nil