If warnings have been disabled (for example with the -W0 flag), does nothing. Otherwise, converts each of the messages to strings, appends a newline character to the string if the string does not end in a newline, and calls Warning.warn with the string.
warn("warning 1", "warning 2")
<em>produces:</em>
warning 1
warning 2
If the uplevel keyword argument is given, the string will be prepended with information for the given caller frame in the same format used by the rb_warn C function.
# In baz.rb
def foo
warn("invalid call to foo", uplevel: 1)
end
def bar
foo
end
bar
<em>produces:</em>
baz.rb:6: warning: invalid call to foo
If category keyword argument is given, passes the category to Warning.warn. The category given must be be one of the following categories:
Used for warning for deprecated functionality that may be removed in the future.
Used for experimental features that may change in future releases.
With a block given, returns an array of two arrays:
The first having those elements for which the block returns a truthy value.
The other having all other elements.
Examples:
p = (1..4).partition {|i| i.even? } p # => [[2, 4], [1, 3]] p = ('a'..'d').partition {|c| c < 'c' } p # => [["a", "b"], ["c", "d"]] h = {foo: 0, bar: 1, baz: 2, bat: 3} p = h.partition {|key, value| key.start_with?('b') } p # => [[[:bar, 1], [:baz, 2], [:bat, 3]], [[:foo, 0]]] p = h.partition {|key, value| value < 2 } p # => [[[:foo, 0], [:bar, 1]], [[:baz, 2], [:bat, 3]]]
With no block given, returns an Enumerator.
Related: Enumerable#group_by.
Writes warning message msg to $stderr. This method is called by Ruby for all emitted warnings. A category may be included with the warning.
See the documentation of the Warning module for how to customize this.
Enables the coverage measurement. See the documentation of Coverage class in detail. This is equivalent to Coverage.setup and Coverage.resume.
Returns a memory pointer of a function’s hexadecimal address location val
Example:
lib = Fiddle.dlopen('/lib64/libc-2.15.so')
=> #<Fiddle::Handle:0x00000001342460>
Fiddle.dlwrap(lib['strcpy'].to_s(16))
=> 25522520
Returns the hexadecimal representation of a memory pointer address addr
Example:
lib = Fiddle.dlopen('/lib64/libc-2.15.so')
=> #<Fiddle::Handle:0x00000001342460>
lib['strcpy'].to_s(16)
=> "7f59de6dd240"
Fiddle.dlunwrap(Fiddle.dlwrap(lib['strcpy'].to_s(16)))
=> "7f59de6dd240"
Returns the Ruby objects created by parsing the given source.
Argument source contains the String to be parsed.
Argument opts, if given, contains a Hash of options for the parsing. See Parsing Options.
When source is a JSON array, returns a Ruby Array:
source = '["foo", 1.0, true, false, null]' ruby = JSON.parse(source) ruby # => ["foo", 1.0, true, false, nil] ruby.class # => Array
When source is a JSON object, returns a Ruby Hash:
source = '{"a": "foo", "b": 1.0, "c": true, "d": false, "e": null}' ruby = JSON.parse(source) ruby # => {"a"=>"foo", "b"=>1.0, "c"=>true, "d"=>false, "e"=>nil} ruby.class # => Hash
For examples of parsing for all JSON data types, see Parsing JSON.
Parses nested JSON objects:
source = <<-EOT { "name": "Dave", "age" :40, "hats": [ "Cattleman's", "Panama", "Tophat" ] } EOT ruby = JSON.parse(source) ruby # => {"name"=>"Dave", "age"=>40, "hats"=>["Cattleman's", "Panama", "Tophat"]}
Raises an exception if source is not valid JSON:
# Raises JSON::ParserError (783: unexpected token at ''): JSON.parse('')
Calls
parse(source, opts)
with source and possibly modified opts.
Differences from JSON.parse:
Option max_nesting, if not provided, defaults to false, which disables checking for nesting depth.
Option allow_nan, if not provided, defaults to true.
Returns a String containing the generated JSON data.
See also JSON.fast_generate, JSON.pretty_generate.
Argument obj is the Ruby object to be converted to JSON.
Argument opts, if given, contains a Hash of options for the generation. See Generating Options.
When obj is an Array, returns a String containing a JSON array:
obj = ["foo", 1.0, true, false, nil] json = JSON.generate(obj) json # => '["foo",1.0,true,false,null]'
When obj is a Hash, returns a String containing a JSON object:
obj = {foo: 0, bar: 's', baz: :bat} json = JSON.generate(obj) json # => '{"foo":0,"bar":"s","baz":"bat"}'
For examples of generating from other Ruby objects, see Generating JSON from Other Objects.
Raises an exception if any formatting option is not a String.
Raises an exception if obj contains circular references:
a = []; b = []; a.push(b); b.push(a) # Raises JSON::NestingError (nesting of 100 is too deep): JSON.generate(a)
See any remaining errors held in queue.
Any errors you see here are probably due to a bug in Ruby’s OpenSSL implementation.
Parse a YAML string in yaml. Returns the Psych::Nodes::Document. filename is used in the exception message if a Psych::SyntaxError is raised.
Raises a Psych::SyntaxError when a YAML syntax error is detected.
Example:
Psych.parse("---\n - a\n - b") # => #<Psych::Nodes::Document:0x00> begin Psych.parse("--- `", filename: "file.txt") rescue Psych::SyntaxError => ex ex.file # => 'file.txt' ex.message # => "(file.txt): found character that cannot start any token" end
See Psych::Nodes for more information about YAML AST.
Returns a default parser
Change what’s displayed on the screen to reflect the current contents.
See GNU Readline’s rl_redisplay function.
Raises NotImplementedError if the using readline library does not support.
Returns true if filepath points to a character device, false otherwise.
File.chardev?($stdin) # => true File.chardev?('t.txt') # => false
Initiates garbage collection, even if manually disabled.
This method is defined with keyword arguments that default to true:
def GC.start(full_mark: true, immediate_sweep: true); end
Use full_mark: false to perform a minor GC. Use immediate_sweep: false to defer sweeping (use lazy sweep).
Note: These keyword arguments are implementation and version dependent. They are not guaranteed to be future-compatible, and may be ignored if the underlying implementation does not support them.
Invokes the block with a Benchmark::Report object, which may be used to collect and report on the results of individual benchmark tests. Reserves label_width leading spaces for labels on each line. Prints caption at the top of the report, and uses format to format each line. (Note: caption must contain a terminating newline character, see the default Benchmark::Tms::CAPTION for an example.)
Returns an array of Benchmark::Tms objects.
If the block returns an array of Benchmark::Tms objects, these will be used to format additional lines of output. If labels parameter are given, these are used to label these extra lines.
Note: Other methods provide a simpler interface to this one, and are suitable for nearly all benchmarking requirements. See the examples in Benchmark, and the bm and bmbm methods.
Example:
require 'benchmark' include Benchmark # we need the CAPTION and FORMAT constants n = 5000000 Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x| tf = x.report("for:") { for i in 1..n; a = "1"; end } tt = x.report("times:") { n.times do ; a = "1"; end } tu = x.report("upto:") { 1.upto(n) do ; a = "1"; end } [tf+tt+tu, (tf+tt+tu)/3] end
Generates:
user system total real for: 0.970000 0.000000 0.970000 ( 0.970493) times: 0.990000 0.000000 0.990000 ( 0.989542) upto: 0.970000 0.000000 0.970000 ( 0.972854) >total: 2.930000 0.000000 2.930000 ( 2.932889) >avg: 0.976667 0.000000 0.976667 ( 0.977630)
Invokes the block with a Benchmark::Report object, which may be used to collect and report on the results of individual benchmark tests. Reserves label_width leading spaces for labels on each line. Prints caption at the top of the report, and uses format to format each line. (Note: caption must contain a terminating newline character, see the default Benchmark::Tms::CAPTION for an example.)
Returns an array of Benchmark::Tms objects.
If the block returns an array of Benchmark::Tms objects, these will be used to format additional lines of output. If labels parameter are given, these are used to label these extra lines.
Note: Other methods provide a simpler interface to this one, and are suitable for nearly all benchmarking requirements. See the examples in Benchmark, and the bm and bmbm methods.
Example:
require 'benchmark' include Benchmark # we need the CAPTION and FORMAT constants n = 5000000 Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x| tf = x.report("for:") { for i in 1..n; a = "1"; end } tt = x.report("times:") { n.times do ; a = "1"; end } tu = x.report("upto:") { 1.upto(n) do ; a = "1"; end } [tf+tt+tu, (tf+tt+tu)/3] end
Generates:
user system total real for: 0.970000 0.000000 0.970000 ( 0.970493) times: 0.990000 0.000000 0.990000 ( 0.989542) upto: 0.970000 0.000000 0.970000 ( 0.972854) >total: 2.930000 0.000000 2.930000 ( 2.932889) >avg: 0.976667 0.000000 0.976667 ( 0.977630)
URI::parse(uri_str)
Creates one of the URI’s subclasses instance from the string.
URI::InvalidURIError
Raised if URI given is not a correct one.
require 'uri' uri = URI.parse("http://www.ruby-lang.org/") # => #<URI::HTTP http://www.ruby-lang.org/> uri.scheme # => "http" uri.host # => "www.ruby-lang.org"
It’s recommended to first ::escape the provided uri_str if there are any invalid URI characters.
URI::extract(str[, schemes][,&blk])
Extracts URIs from a string. If block given, iterates through all matched URIs. Returns nil if block given or array with matches.
require "uri" URI.extract("text here http://foo.example.org/bla and here mailto:test@example.com and here also.") # => ["http://foo.example.com/bla", "mailto:test@example.com"]
The standard configuration object for gems.
Use the given configuration object (which implements the ConfigFile protocol) as the standard configuration object.
Returns the name of the script being executed. The value is not affected by assigning a new value to $0.
This method first appeared in Ruby 2.1 to serve as a global variable free means to get the script name.
Specifies the handling of signals. The first parameter is a signal name (a string such as “SIGALRM”, “SIGUSR1”, and so on) or a signal number. The characters “SIG” may be omitted from the signal name. The command or block specifies code to be run when the signal is raised. If the command is the string “IGNORE” or “SIG_IGN”, the signal will be ignored. If the command is “DEFAULT” or “SIG_DFL”, the Ruby’s default handler will be invoked. If the command is “EXIT”, the script will be terminated by the signal. If the command is “SYSTEM_DEFAULT”, the operating system’s default handler will be invoked. Otherwise, the given command or block will be run. The special signal name “EXIT” or signal number zero will be invoked just prior to program termination. trap returns the previous handler for the given signal.
Signal.trap(0, proc { puts "Terminating: #{$$}" }) Signal.trap("CLD") { puts "Child died" } fork && Process.wait
produces:
Terminating: 27461 Child died Terminating: 27460