Returns true if the named files are identical.
file_1 and file_2 can be an IO object.
open("a", "w") {} p File.identical?("a", "a") #=> true p File.identical?("a", "./a") #=> true File.link("a", "b") p File.identical?("a", "b") #=> true File.symlink("a", "c") p File.identical?("a", "c") #=> true open("d", "w") {} p File.identical?("a", "d") #=> false
Returns the list of loaded encodings.
Encoding.list #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>, #<Encoding:ISO-2022-JP (dummy)>] Encoding.find("US-ASCII") #=> #<Encoding:US-ASCII> Encoding.list #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>, #<Encoding:US-ASCII>, #<Encoding:ISO-2022-JP (dummy)>]
Returns the hash of available encoding alias and original encoding name.
Encoding.aliases
#=> {"BINARY"=>"ASCII-8BIT", "ASCII"=>"US-ASCII", "ANSI_X3.4-1968"=>"US-ASCII",
"SJIS"=>"Windows-31J", "eucJP"=>"EUC-JP", "CP932"=>"Windows-31J"}
Creates an infinite enumerator from any block, just called over and over. The result of the previous iteration is passed to the next one. If initial is provided, it is passed to the first iteration, and becomes the first element of the enumerator; if it is not provided, the first iteration receives nil, and its result becomes the first element of the iterator.
Raising StopIteration from the block stops an iteration.
Enumerator.produce(1, &:succ) # => enumerator of 1, 2, 3, 4, .... Enumerator.produce { rand(10) } # => infinite random number sequence ancestors = Enumerator.produce(node) { |prev| node = prev.parent or raise StopIteration } enclosing_section = ancestors.find { |n| n.type == :section }
Using ::produce together with Enumerable methods like Enumerable#detect, Enumerable#slice_after, Enumerable#take_while can provide Enumerator-based alternatives for while and until cycles:
# Find next Tuesday require "date" Enumerator.produce(Date.today, &:succ).detect(&:tuesday?) # Simple lexer: require "strscan" scanner = StringScanner.new("7+38/6") PATTERN = %r{\d+|[-/+*]} Enumerator.produce { scanner.scan(PATTERN) }.slice_after { scanner.eos? }.first # => ["7", "+", "38", "/", "6"]
Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
With message nil, returns self:
x0 = StandardError.new('Boom') # => #<StandardError: Boom> x1 = x0.exception # => #<StandardError: Boom> x0.__id__ == x1.__id__ # => true
With string-convertible object message (even the same as the original message), returns a new exception object whose class is the same as self, and whose message is the given message:
x1 = x0.exception('Boom') # => #<StandardError: Boom> x0..equal?(x1) # => false
Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
With message nil, returns self:
x0 = StandardError.new('Boom') # => #<StandardError: Boom> x1 = x0.exception # => #<StandardError: Boom> x0.__id__ == x1.__id__ # => true
With string-convertible object message (even the same as the original message), returns a new exception object whose class is the same as self, and whose message is the given message:
x1 = x0.exception('Boom') # => #<StandardError: Boom> x0..equal?(x1) # => false
Returns the backtrace (the list of code locations that led to the exception), as an array of strings.
Example (assuming the code is stored in the file named t.rb):
def division(numerator, denominator) numerator / denominator end begin division(1, 0) rescue => ex p ex.backtrace # ["t.rb:2:in 'Integer#/'", "t.rb:2:in 'Object#division'", "t.rb:6:in '<main>'"] loc = ex.backtrace.first p loc.class # String end
The value returned by this method migth be adjusted when raising (see Kernel#raise), or during intermediate handling by set_backtrace.
See also backtrace_locations that provide the same value, as structured objects. (Note though that two values might not be consistent with each other when backtraces are manually adjusted.)
see Backtraces.
Returns true if exiting successful, false if not.
Return the receiver associated with this KeyError exception.
Return the receiver associated with this NameError exception.
Return the receiver associated with this FrozenError exception.
Returns a list of modules included/prepended in mod (including mod itself).
module Mod include Math include Comparable prepend Enumerable end Mod.ancestors #=> [Enumerable, Mod, Comparable, Math] Math.ancestors #=> [Math] Enumerable.ancestors #=> [Enumerable]
Returns true if the date is before the date of calendar reform, false otherwise:
(Date.new(1582, 10, 15) - 1).julian? # => true Date.new(1582, 10, 15).julian? # => false
Equivalent to Date#new_start with argument Date::JULIAN.
Returns a new Time object whose numerical value is greater than or equal to self with its seconds truncated to precision ndigits:
t = Time.utc(2010, 3, 30, 5, 43, 25.123456789r) t # => 2010-03-30 05:43:25.123456789 UTC t.ceil # => 2010-03-30 05:43:26 UTC t.ceil(2) # => 2010-03-30 05:43:25.13 UTC t.ceil(4) # => 2010-03-30 05:43:25.1235 UTC t.ceil(6) # => 2010-03-30 05:43:25.123457 UTC t.ceil(8) # => 2010-03-30 05:43:25.12345679 UTC t.ceil(10) # => 2010-03-30 05:43:25.123456789 UTC t = Time.utc(1999, 12, 31, 23, 59, 59) t # => 1999-12-31 23:59:59 UTC (t + 0.4).ceil # => 2000-01-01 00:00:00 UTC (t + 0.9).ceil # => 2000-01-01 00:00:00 UTC (t + 1.4).ceil # => 2000-01-01 00:00:01 UTC (t + 1.9).ceil # => 2000-01-01 00:00:01 UTC
Related: Time#floor, Time#round.
Returns an array of all lines read from the stream.
When called from class IO (but not subclasses of IO), this method has potential security vulnerabilities if called with untrusted input; see Command Injection.
The first argument must be a string that is the path to a file.
With only argument path given, parses lines from the file at the given path, as determined by the default line separator, and returns those lines in an array:
IO.readlines('t.txt') # => ["First line\n", "Second line\n", "\n", "Third line\n", "Fourth line\n"]
With argument sep given, parses lines as determined by that line separator (see Line Separator):
# Ordinary separator. IO.readlines('t.txt', 'li') # =>["First li", "ne\nSecond li", "ne\n\nThird li", "ne\nFourth li", "ne\n"] # Get-paragraphs separator. IO.readlines('t.txt', '') # => ["First line\nSecond line\n\n", "Third line\nFourth line\n"] # Get-all separator. IO.readlines('t.txt', nil) # => ["First line\nSecond line\n\nThird line\nFourth line\n"]
With argument limit given, parses lines as determined by the default line separator and the given line-length limit (see Line Separator and Line Limit:
IO.readlines('t.txt', 7) # => ["First l", "ine\n", "Second ", "line\n", "\n", "Third l", "ine\n", "Fourth ", "line\n"]
With arguments sep and limit given, combines the two behaviors (see Line Separator and Line Limit).
Optional keyword arguments opts specify:
Encoding options.
Returns the current line number for the stream; see Line Number.
Sets and returns the line number for the stream; see Line Number.
Reads and returns all remaining line from the stream; does not modify $_. See Line IO.
With no arguments given, returns lines as determined by line separator $/, or nil if none:
f = File.new('t.txt') f.readlines # => ["First line\n", "Second line\n", "\n", "Fourth line\n", "Fifth line\n"] f.readlines # => [] f.close
With only string argument sep given, returns lines as determined by line separator sep, or nil if none; see Line Separator:
f = File.new('t.txt') f.readlines('li') # => ["First li", "ne\nSecond li", "ne\n\nFourth li", "ne\nFifth li", "ne\n"] f.close
The two special values for sep are honored:
f = File.new('t.txt') # Get all into one string. f.readlines(nil) # => ["First line\nSecond line\n\nFourth line\nFifth line\n"] # Get paragraphs (up to two line separators). f.rewind f.readlines('') # => ["First line\nSecond line\n\n", "Fourth line\nFifth line\n"] f.close
With only integer argument limit given, limits the number of bytes in each line; see Line Limit:
f = File.new('t.txt') f.readlines(8) # => ["First li", "ne\n", "Second l", "ine\n", "\n", "Fourth l", "ine\n", "Fifth li", "ne\n"] f.close
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.readlines(chomp: true) # => ["First line", "Second line", "", "Fourth line", "Fifth line"] f.close
Reads a line as with IO#gets, but raises EOFError if already at end-of-stream.
Optional keyword argument chomp specifies whether line separators are to be omitted.
Returns the smallest number greater than or equal to rat with a precision of ndigits decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.
Returns a rational when ndigits is positive, otherwise returns an integer.
Rational(3).ceil #=> 3 Rational(2, 3).ceil #=> 1 Rational(-3, 2).ceil #=> -1 # decimal - 1 2 3 . 4 5 6 # ^ ^ ^ ^ ^ ^ # precision -3 -2 -1 0 +1 +2 Rational('-123.456').ceil(+1).to_f #=> -123.4 Rational('-123.456').ceil(-1) #=> -120
Returns a simpler approximation of the value if the optional argument eps is given (rat-|eps| <= result <= rat+|eps|), self otherwise.
r = Rational(5033165, 16777216) r.rationalize #=> (5033165/16777216) r.rationalize(Rational('0.01')) #=> (3/10) r.rationalize(Rational('0.1')) #=> (1/3)
Returns the original string of self:
/ab+c/ix.source # => "ab+c"
Regexp escape sequences are retained:
/\x20\+/.source # => "\\x20\\+"
Lexer escape characters are not retained:
/\//.source # => "/"
Replaces the contents of the set with the contents of the given enumerable object and returns self.
set = Set[1, 'c', :s] #=> #<Set: {1, "c", :s}> set.replace([1, 2]) #=> #<Set: {1, 2}> set #=> #<Set: {1, 2}>