Compiled source code (String) on *eval methods on the :script_compiled event. If loaded from a file, it will return nil.
Returns an array of the names of global variables. This includes special regexp global variables such as $~ and $+, but does not include the numbered regexp global variables ($1, $2, etc.).
global_variables.grep /std/ #=> [:$stdin, :$stdout, :$stderr]
Controls tracing of assignments to global variables. The parameter symbol identifies the variable (as either a string name or a symbol identifier). cmd (which may be a string or a Proc object) or block is executed whenever the variable is assigned. The block or Proc object receives the variable’s new value as a parameter. Also see Kernel::untrace_var.
trace_var :$_, proc {|v| puts "$_ is now '#{v}'" } $_ = "hello" $_ = ' there'
produces:
$_ is now 'hello' $_ is now ' there'
Removes tracing for the specified command on the given global variable and returns nil. If no command is specified, removes all tracing for that variable and returns an array containing the commands actually removed.
Returns a pretty printed object as a string.
See the PP module for more information.
Returns the names of the current local variables.
fred = 1 for i in 1..10 # ... end local_variables #=> [:fred, :i]
Returns an array containing elements selected by the block.
With a block given, calls the block with successive elements; returns an array of those elements for which the block returns a truthy value:
(0..9).select {|element| element % 3 == 0 } # => [0, 3, 6, 9] a = {foo: 0, bar: 1, baz: 2}.select {|key, value| key.start_with?('b') } a # => {:bar=>1, :baz=>2}
With no block given, returns an Enumerator.
Related: reject.
Returns the elements for which the block returns the minimum values.
With a block given and no argument, returns the element for which the block returns the minimum value:
(1..4).min_by {|element| -element } # => 4 %w[a b c d].min_by {|element| -element.ord } # => "d" {foo: 0, bar: 1, baz: 2}.min_by {|key, value| -value } # => [:baz, 2] [].min_by {|element| -element } # => nil
With a block given and positive integer argument n given, returns an array containing the n elements for which the block returns minimum values:
(1..4).min_by(2) {|element| -element } # => [4, 3] %w[a b c d].min_by(2) {|element| -element.ord } # => ["d", "c"] {foo: 0, bar: 1, baz: 2}.min_by(2) {|key, value| -value } # => [[:baz, 2], [:bar, 1]] [].min_by(2) {|element| -element } # => []
Returns an Enumerator if no block is given.
Returns a 2-element array containing the elements for which the block returns minimum and maximum values:
(1..4).minmax_by {|element| -element } # => [4, 1] %w[a b c d].minmax_by {|element| -element.ord } # => ["d", "a"] {foo: 0, bar: 1, baz: 2}.minmax_by {|key, value| -value } # => [[:baz, 2], [:foo, 0]] [].minmax_by {|element| -element } # => [nil, nil]
Returns an Enumerator if no block is given.
Calls the given block with each element, converting multiple values from yield to an array; returns self:
a = [] (1..4).each_entry {|element| a.push(element) } # => 1..4 a # => [1, 2, 3, 4] a = [] h = {foo: 0, bar: 1, baz:2} h.each_entry {|element| a.push(element) } # => {:foo=>0, :bar=>1, :baz=>2} a # => [[:foo, 0], [:bar, 1], [:baz, 2]] class Foo include Enumerable def each yield 1 yield 1, 2 yield end end Foo.new.each_entry {|yielded| p yielded }
Output:
1 [1, 2] nil
With no block given, returns an Enumerator.
Returns the last Error of the current executing Thread or nil if none
Sets the last Error of the current executing Thread to error
Arguments obj and opts here are the same as arguments obj and opts in JSON.generate.
By default, generates JSON data without checking for circular references in obj (option max_nesting set to false, disabled).
Raises an exception if obj contains circular references:
a = []; b = []; a.push(b); b.push(a) # Raises SystemStackError (stack level too deep): JSON.fast_generate(a)
Initializes the MonitorMixin after being included in a class or when an object has been extended with the MonitorMixin
Returns the original line from source for from the given object.
See ::trace_object_allocations for more information and examples.
Combine two Adler-32 check values in to one. adler1 is the first Adler-32 value, adler2 is the second Adler-32 value. len2 is the length of the string used to generate adler2.
Combine two CRC-32 check values in to one. crc1 is the first CRC-32 value, crc2 is the second CRC-32 value. len2 is the length of the string used to generate crc2.
Returns true if the named file is writable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.
If file_name is writable by others, returns an integer representing the file permission bits of file_name. Returns nil otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2).
file_name can be an IO object.
File.world_writable?("/tmp") #=> 511 m = File.world_writable?("/tmp") sprintf("%o", m) #=> "777"
Returns information for heaps in the GC.
If the first optional argument, heap_name, is passed in and not nil, it returns a Hash containing information about the particular heap. Otherwise, it will return a Hash with heap names as keys and a Hash containing information about the heap as values.
If the second optional argument, hash_or_key, is given as Hash, it will be overwritten and returned. This is intended to avoid the probe effect.
If both optional arguments are passed in and the second optional argument is a symbol, it will return a Numeric of the value for the particular heap.
On CRuby, heap_name is of the type Integer but may be of type String on other implementations.
The contents of the hash are implementation specific and may change in the future without notice.
If the optional argument, hash, is given, it is overwritten and returned.
This method is only expected to work on CRuby.
The hash includes the following keys about the internal information in the GC:
The slot size of the heap in bytes.
The number of pages that can be allocated without triggering a new garbage collection cycle.
The number of pages in the eden heap.
The total number of slots in all of the pages in the eden heap.
The number of pages in the tomb heap. The tomb heap only contains pages that do not have any live objects.
The total number of slots in all of the pages in the tomb heap.
The total number of pages that have been allocated in the heap.
The total number of pages that have been freed and released back to the system in the heap.
The number of times major garbage collection cycles this heap has forced to start due to running out of free slots.
The number of times this heap has forced incremental marking to complete due to running out of pooled slots.
Try to activate a gem containing path. Returns true if activation succeeded or wasn’t needed because it was already activated. Returns false if it can’t find the path in a gem.
Find the full path to the executable for gem name. If the exec_name is not given, an exception will be raised, otherwise the specified executable’s path is returned. requirements allows you to specify specific gem versions.
The mode needed to read a file as straight binary.
Returns a list of paths matching glob that can be used by a gem to pick up features from other gems. For example:
Gem.find_files('rdoc/discover').each do |path| load path end
if check_load_path is true (the default), then find_files also searches $LOAD_PATH for files as well as gems.
Note that find_files will return all files even if they are from different versions of the same gem. See also find_latest_files