Returns the return value of the iterator.
o = Object.new def o.each yield 1 yield 2 yield 3 100 end e = o.to_enum puts e.next #=> 1 puts e.next #=> 2 puts e.next #=> 3 begin e.next rescue StopIteration => ex puts ex.result #=> 100 end
Prevents further modifications to obj. A FrozenError will be raised if modification is attempted. There is no way to unfreeze a frozen object. See also Object#frozen?.
This method returns self.
a = [ "a", "b", "c" ] a.freeze a << "z"
produces:
prog.rb:3:in `<<': can't modify frozen Array (FrozenError) from prog.rb:3
Objects of the following classes are always frozen: Integer, Float, Symbol.
Invokes Module.prepend_features on each parameter in reverse order.
The equivalent of included, but for prepended modules.
module A def self.prepended(mod) puts "#{self} prepended to #{mod}" end end module Enumerable prepend A end # => prints "A prepended to Enumerable"
Returns a hash of values parsed from string, which should be a valid XML date format:
d = Date.new(2001, 2, 3) s = d.xmlschema # => "2001-02-03" Date._xmlschema(s) # => {:year=>2001, :mon=>2, :mday=>3}
See argument limit.
Related: Date.xmlschema (returns a Date object).
Returns a new Date object with values parsed from string, which should be a valid XML date format:
d = Date.new(2001, 2, 3) s = d.xmlschema # => "2001-02-03" Date.xmlschema(s) # => #<Date: 2001-02-03>
See:
Argument start.
Argument limit.
Related: Date._xmlschema (returns a hash).
Returns true if the date is on or after the date of calendar reform, false otherwise:
Date.new(1582, 10, 15).gregorian? # => true (Date.new(1582, 10, 15) - 1).gregorian? # => false
Equivalent to Date#new_start with argument Date::GREGORIAN.
Equivalent to strftime with argument '%Y-%m-%d' (or its shorthand form '%F');
Date.new(2001, 2, 3).iso8601 # => "2001-02-03"
Creates a new DateTime object by parsing from a string according to some typical XML Schema formats.
DateTime.xmlschema('2001-02-03T04:05:06+07:00') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
Raise an ArgumentError when the string length is longer than limit. You can stop this check by passing limit: nil, but note that it may take a long time to parse.
This method is equivalent to strftime(‘%FT%T%:z’). The optional argument n is the number of digits for fractional seconds.
DateTime.parse('2001-02-03T04:05:06.123456789+07:00').iso8601(9) #=> "2001-02-03T04:05:06.123456789+07:00"
Parses time as a dateTime defined by the XML Schema and converts it to a Time object. The format is a restricted version of the format defined by ISO 8601.
ArgumentError is raised if time is not compliant with the format or if the Time class cannot represent the specified time.
See xmlschema for more information on this format.
require 'time' Time.xmlschema("2011-10-05T22:26:12-04:00") #=> 2011-10-05 22:26:12-04:00
You must require ‘time’ to use this method.
Returns a string which represents the time as a dateTime defined by XML Schema:
CCYY-MM-DDThh:mm:ssTZD CCYY-MM-DDThh:mm:ss.sssTZD
where TZD is Z or [+-]hh:mm.
If self is a UTC time, Z is used as TZD. [+-]hh:mm is used otherwise.
fraction_digits specifies a number of digits to use for fractional seconds. Its default value is 0.
require 'time' t = Time.now t.iso8601 # => "2011-10-05T22:26:12-04:00"
You must require ‘time’ to use this method.
Returns true if key is pressed. key may be a virtual key code or its name (String or Symbol) with out “VK_” prefix.
This method is Windows only.
You must require ‘io/console’ to use this method.
Returns number of bytes that can be read without blocking. Returns zero if no information available.
You must require ‘io/wait’ to use this method.
Returns a truthy value if input available without blocking, or a falsy value.
You must require ‘io/wait’ to use this method.
Calls the block with each successive line 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 calls the block with each successive line:
File.foreach('t.txt') {|line| p line }
Output: the same as above.
For both forms, command and path, the remaining arguments are the same.
With argument sep given, parses lines as determined by that line separator (see Line Separator):
File.foreach('t.txt', 'li') {|line| p line }
Output:
"First li" "ne\nSecond li" "ne\n\nThird li" "ne\nFourth li" "ne\n"
Each paragraph:
File.foreach('t.txt', '') {|paragraph| p paragraph }
Output:
"First line\nSecond line\n\n" "Third 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):
File.foreach('t.txt', 7) {|line| p line }
Output:
"First l" "ine\n" "Second " "line\n" "\n" "Third l" "ine\n" "Fourth l" "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 an Enumerator if no block is given.
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.
Opens the stream, reads and returns some or all of its content, and closes the stream; returns nil if no bytes were read.
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, reads in text mode and returns the entire content of the file at the given path:
IO.read('t.txt') # => "First line\nSecond line\n\nThird line\nFourth line\n"
On Windows, text mode can terminate reading and leave bytes in the file unread when encountering certain special bytes. Consider using IO.binread if all bytes in the file should be read.
With argument length, returns length bytes if available:
IO.read('t.txt', 7) # => "First l" IO.read('t.txt', 700) # => "First line\r\nSecond line\r\n\r\nFourth line\r\nFifth line\r\n"
With arguments length and offset, returns length bytes if available, beginning at the given offset:
IO.read('t.txt', 10, 2) # => "rst line\nS" IO.read('t.txt', 10, 200) # => nil
Optional keyword arguments opts specify:
Encoding options.
Behaves like IO.read, except that the stream is opened in binary mode with ASCII-8BIT encoding.
When called from class IO (but not subclasses of IO), this method has potential security vulnerabilities if called with untrusted input; see Command Injection.
Reassociates the stream with another stream, which may be of a different class. This method may be used to redirect an existing stream to a new destination.
With argument other_io given, reassociates with that stream:
# Redirect $stdin from a file. f = File.open('t.txt') $stdin.reopen(f) f.close # Redirect $stdout to a file. f = File.open('t.tmp', 'w') $stdout.reopen(f) f.close
With argument path given, reassociates with a new stream to that file path:
$stdin.reopen('t.txt') $stdout.reopen('t.tmp', 'w')
Optional keyword arguments opts specify:
Encoding options.
Behaves like IO#readpartial, except that it uses low-level system functions.
This method should not be used with other stream-reader methods.
Behaves like IO#readpartial, except that it:
Reads at the given offset (in bytes).
Disregards, and does not modify, the stream’s position (see Position).
Bypasses any user space buffering in the stream.
Because this method does not disturb the stream’s state (its position, in particular), pread allows multiple threads and processes to use the same IO object for reading at various offsets.
f = File.open('t.txt') f.read # => "First line\nSecond line\n\nFourth line\nFifth line\n" f.pos # => 52 # Read 12 bytes at offset 0. f.pread(12, 0) # => "First line\n" # Read 9 bytes at offset 8. f.pread(9, 8) # => "ne\nSecon" f.close
Not available on some platforms.