Results for: "fnmatch"

Iterates over all hostnames for address.

Iterates over all IP addresses for name.

Iterates over all hostnames for address.

Sets the system path (the Shell instance’s PATH environment variable).

path should be an array of directory name strings.

Convenience method for Shell::CommandProcessor.alias_command. Defines an instance method which will execute a command under an alternative name.

Shell.def_system_command('date')
Shell.alias_command('date_in_utc', 'date', '-u')
Shell.new.date_in_utc # => Sat Jan 25 16:59:57 UTC 2014

Convenience method for Shell::CommandProcessor.unalias_command

Returns the execution stack for the target thread—an array containing backtrace location objects.

See Thread::Backtrace::Location for more information.

This method behaves similarly to Kernel#caller_locations except it applies to a specific thread.

Returns the Ruby source filename and line number containing this proc or nil if this proc was not defined in Ruby (i.e. native).

Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native).

Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native).

Converts block to a Proc object (and therefore binds it at the point of call) and registers it for execution when the program exits. If multiple handlers are registered, they are executed in reverse order of registration.

def do_at_exit(str1)
  at_exit { print str1 }
end
at_exit { puts "cruel world" }
do_at_exit("goodbye ")
exit

produces:

goodbye cruel world

Ruby tries to load the library named string relative to the requiring file’s path. If the file’s path cannot be determined a LoadError is raised. If a file is loaded true is returned and false otherwise.

Returns the current execution stack—an array containing backtrace location objects.

See Thread::Backtrace::Location for more information.

The optional start parameter determines the number of initial stack entries to omit from the top of the stack.

A second optional length parameter can be used to limit how many entries are returned from the stack.

Returns nil if start is greater than the size of current execution stack.

Optionally you can pass a range, which will return an array containing the entries within the specified range.

Returns a new array with the concatenated results of running block once for every element in enum.

If no block is given, an enumerator is returned instead.

[1, 2, 3, 4].flat_map { |e| [e, -e] } #=> [1, -1, 2, -2, 3, -3, 4, -4]
[[1, 2], [3, 4]].flat_map { |e| e + [100] } #=> [1, 2, 100, 3, 4, 100]

Returns the object in enum that gives the maximum value from the given block.

If no block is given, an enumerator is returned instead.

a = %w(albatross dog horse)
a.max_by { |x| x.length }   #=> "albatross"

If the n argument is given, maximum n elements are returned as an array. These n elements are sorted by the value from the given block, in descending order.

a = %w[albatross dog horse]
a.max_by(2) {|x| x.length } #=> ["albatross", "horse"]

enum.max_by(n) can be used to implement weighted random sampling. Following example implements and use Enumerable#wsample.

module Enumerable
  # weighted random sampling.
  #
  # Pavlos S. Efraimidis, Paul G. Spirakis
  # Weighted random sampling with a reservoir
  # Information Processing Letters
  # Volume 97, Issue 5 (16 March 2006)
  def wsample(n)
    self.max_by(n) {|v| rand ** (1.0/yield(v)) }
  end
end
e = (-20..20).to_a*10000
a = e.wsample(20000) {|x|
  Math.exp(-(x/5.0)**2) # normal distribution
}
# a is 20000 samples from e.
p a.length #=> 20000
h = a.group_by {|x| x }
-10.upto(10) {|x| puts "*" * (h[x].length/30.0).to_i if h[x] }
#=> *
#   ***
#   ******
#   ***********
#   ******************
#   *****************************
#   *****************************************
#   ****************************************************
#   ***************************************************************
#   ********************************************************************
#   ***********************************************************************
#   ***********************************************************************
#   **************************************************************
#   ****************************************************
#   ***************************************
#   ***************************
#   ******************
#   ***********
#   *******
#   ***
#   *

Builds a temporary array and traverses that array in reverse order.

If no block is given, an enumerator is returned instead.

  (1..3).reverse_each { |v| p v }

produces:

  3
  2
  1

Calls block once for each element in self, passing that element as a parameter, converting multiple values from yield to an array.

If no block is given, an enumerator is returned instead.

class Foo
  include Enumerable
  def each
    yield 1
    yield 1, 2
    yield
  end
end
Foo.new.each_entry{ |o| p o }

produces:

1
[1, 2]
nil

Iterates the given block for each slice of <n> elements. If no block is given, returns an enumerator.

(1..10).each_slice(3) { |a| p a }
# outputs below
[1, 2, 3]
[4, 5, 6]
[7, 8, 9]
[10]

Iterates the given block for each array of consecutive <n> elements. If no block is given, returns an enumerator.

e.g.:

(1..10).each_cons(3) { |a| p a }
# outputs below
[1, 2, 3]
[2, 3, 4]
[3, 4, 5]
[4, 5, 6]
[5, 6, 7]
[6, 7, 8]
[7, 8, 9]
[8, 9, 10]

Creates an enumerator for each chunked elements. The beginnings of chunks are defined by the block.

This method split each chunk using adjacent elements, elt_before and elt_after, in the receiver enumerator. This method split chunks between elt_before and elt_after where the block returns false.

The block is called the length of the receiver enumerator minus one.

The result enumerator yields the chunked elements as an array. So each method can be called as follows:

enum.chunk_while { |elt_before, elt_after| bool }.each { |ary| ... }

Other methods of the Enumerator class and Enumerable module, such as to_a, map, etc., are also usable.

For example, one-by-one increasing subsequence can be chunked as follows:

a = [1,2,4,9,10,11,12,15,16,19,20,21]
b = a.chunk_while {|i, j| i+1 == j }
p b.to_a #=> [[1, 2], [4], [9, 10, 11, 12], [15, 16], [19, 20, 21]]
c = b.map {|a| a.length < 3 ? a : "#{a.first}-#{a.last}" }
p c #=> [[1, 2], [4], "9-12", [15, 16], "19-21"]
d = c.join(",")
p d #=> "1,2,4,9-12,15,16,19-21"

Increasing (non-decreasing) subsequence can be chunked as follows:

a = [0, 9, 2, 2, 3, 2, 7, 5, 9, 5]
p a.chunk_while {|i, j| i <= j }.to_a
#=> [[0, 9], [2, 2, 3], [2, 7], [5, 9], [5]]

Adjacent evens and odds can be chunked as follows: (Enumerable#chunk is another way to do it.)

a = [7, 5, 9, 2, 0, 7, 9, 4, 2, 0]
p a.chunk_while {|i, j| i.even? == j.even? }.to_a
#=> [[7, 5, 9], [2, 0], [7, 9], [4, 2, 0]]

Enumerable#slice_when does the same, except splitting when the block returns true instead of false.

Generate a JSON document from the Ruby data structure obj and return it. This method disables the checks for circles in Ruby objects.

WARNING: Be careful not to pass any Ruby data structures with circles as obj argument because this will cause JSON to go into an infinite loop.

Generate a JSON document from the Ruby data structure obj and return it. The returned document is a prettier form of the document returned by unparse.

The opts argument can be used to configure the generator. See the generate method for a more detailed explanation.

Returns the source file origin from the given object.

See ::trace_object_allocations for more information and examples.

Returns the original line from source for from the given object.

See ::trace_object_allocations for more information and examples.