Release code
Returns version string from program_name
, version and release.
Returns the array of captures; equivalent to mtch.to_a[1..-1]
.
f1,f2,f3,f4 = /(.)(.)(\d+)(\d)/.match("THX1138.").captures f1 #=> "H" f2 #=> "X" f3 #=> "113" f4 #=> "8"
This says “you can break a line here if necessary”, and a width
-column text sep
is inserted if a line is not broken at the point.
If sep
is not specified, “ ” is used.
If width
is not specified, sep.length
is used. You will have to specify this when sep
is a multibyte character, for example.
Looks up the first IP address for name
.
Looks up all IP address for name
.
Looks up the first IP address for name
.
Looks up all IP address for name
.
Creates a temporary file as a usual File
object (not a Tempfile
). It does not use finalizer and delegation, which makes it more efficient and reliable.
If no block is given, this is similar to Tempfile.new
except creating File
instead of Tempfile
. In that case, the created file is not removed automatically. You should use File.unlink
to remove it.
If a block is given, then a File
object will be constructed, and the block is invoked with the object as the argument. The File
object will be automatically closed and the temporary file is removed after the block terminates, releasing all resources that the block created. The call returns the value of the block.
In any case, all arguments (basename
, tmpdir
, mode
, and **options
) will be treated the same as for Tempfile.new
.
Tempfile.create('foo', '/home/temp') do |f| # ... do something with f ... end
Checks if the object is shareable by ractors.
Ractor.shareable?(1) #=> true -- numbers and other immutable basic values are frozen Ractor.shareable?('foo') #=> false, unless the string is frozen due to # freeze_string_literals: true Ractor.shareable?('foo'.freeze) #=> true
See also the “Shareable and unshareable objects” section in the Ractor
class docs.
Returns true
if thr
is running or sleeping.
thr = Thread.new { } thr.join #=> #<Thread:0x401b3fb0 dead> Thread.current.alive? #=> true thr.alive? #=> false
Returns true
if the queue is empty.
Returns true
if the queue is empty.
Equivalent to Kernel::gets, except readline
raises EOFError
at end of file.
Returns an array containing the lines returned by calling Kernel.gets(sep)
until the end of file.
Use Kernel#gem
to activate a specific version of gem_name
.
requirements
is a list of version requirements that the specified gem must match, most commonly “= example.version.number”. See Gem::Requirement
for how to specify a version requirement.
If you will be activating the latest version of a gem, there is no need to call Kernel#gem
, Kernel#require
will do the right thing for you.
Kernel#gem
returns true if the gem was activated, otherwise false. If the gem could not be found, didn’t match the version requirements, or a different version was already activated, an exception will be raised.
Kernel#gem
should be called before any require statements (otherwise RubyGems may load a conflicting library version).
Kernel#gem
only loads prerelease versions when prerelease requirements
are given:
gem 'rake', '>= 1.1.a', '< 2'
In older RubyGems versions, the environment variable GEM_SKIP could be used to skip activation of specified gems, for example to test out changes that haven’t been installed yet. Now RubyGems defers to -I and the RUBYLIB environment variable to skip activation of a gem.
Example:
GEM_SKIP=libA:libB ruby -I../libA -I../libB ./mycode.rb
Returns an array of every element in enum for which Pattern === element
. If the optional block is supplied, each matching element is passed to it, and the block’s result is stored in the output array.
(1..100).grep 38..44 #=> [38, 39, 40, 41, 42, 43, 44] c = IO.constants c.grep(/SEEK/) #=> [:SEEK_SET, :SEEK_CUR, :SEEK_END] res = c.grep(/SEEK/) { |v| IO.const_get(v) } res #=> [0, 1, 2]
Inverted version of Enumerable#grep
. Returns an array of every element in enum for which not Pattern === element
.
(1..10).grep_v 2..5 #=> [1, 6, 7, 8, 9, 10] res =(1..10).grep_v(2..5) { |v| v * 2 } res #=> [2, 12, 14, 16, 18, 20]
Returns an array for all elements of enum
for which the given block
returns false
.
If no block is given, an Enumerator
is returned instead.
(1..10).reject { |i| i % 3 == 0 } #=> [1, 2, 4, 5, 7, 8, 10] [1, 2, 3, 4, 5].reject { |num| num.even? } #=> [1, 3, 5]
See also Enumerable#find_all
.