Returns the facility number used in the last call to open()
Returns true if the named file is writable by the effective user and group id of this process. See eaccess(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the effective user/group.
Returns true if filepath points to a character device, false otherwise.
File.chardev?($stdin) # => true File.chardev?('t.txt') # => false
This function compacts objects together in Ruby’s heap. It eliminates unused space (or fragmentation) in the heap by moving objects in to that unused space. This function returns a hash which contains statistics about which objects were moved. See GC.latest_gc_info for details about compaction statistics.
This method is implementation specific and not expected to be implemented in any implementation besides MRI.
To test whether GC compaction is supported, use the idiom:
GC.respond_to?(:compact)
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)
Retrieve the PathSupport object that RubyGems uses to lookup files.
Initialize the filesystem paths to use from env. env is a hash-like object (typically ENV) that is queried for ‘GEM_HOME’, ‘GEM_PATH’, and ‘GEM_SPEC_CACHE’ Keys for the env hash should be Strings, and values of the hash should be Strings or nil.
Get the configuration of the current server.
If there is no current server, this returns the default configuration. See current_server and DRbServer::make_config.
Get the configuration of the current server.
If there is no current server, this returns the default configuration. See current_server and DRbServer::make_config.
Get the front object of the current server.
This raises a DRbServerNotFound error if there is no current server. See current_server.
Get the front object of the current server.
This raises a DRbServerNotFound error if there is no current server. See current_server.
Returns a 9-element array representing the parts of the URI formed from the string uri; each array element is a string or nil:
names = %w[scheme userinfo host port registry path opaque query fragment] values = URI.split('https://john.doe@www.example.com:123/forum/questions/?tag=networking&order=newest#top') names.zip(values) # => [["scheme", "https"], ["userinfo", "john.doe"], ["host", "www.example.com"], ["port", "123"], ["registry", nil], ["path", "/forum/questions/"], ["opaque", nil], ["query", "tag=networking&order=newest"], ["fragment", "top"]]
Splits a string into an array of tokens in the same way the UNIX Bourne shell does.
argv = Shellwords.split('here are "two words"') argv #=> ["here", "are", "two words"]
Note, however, that this is not a command line parser. Shell metacharacters except for the single and double quotes and backslash are not treated as such.
argv = Shellwords.split('ruby my_prog.rb | less') argv #=> ["ruby", "my_prog.rb", "|", "less"]
String#shellsplit is a shortcut for this function.
argv = 'here are "two words"'.shellsplit argv #=> ["here", "are", "two words"]
Splits a string into an array of tokens in the same way the UNIX Bourne shell does.
argv = Shellwords.split('here are "two words"') argv #=> ["here", "are", "two words"]
Note, however, that this is not a command line parser. Shell metacharacters except for the single and double quotes and backslash are not treated as such.
argv = Shellwords.split('ruby my_prog.rb | less') argv #=> ["ruby", "my_prog.rb", "|", "less"]
String#shellsplit is a shortcut for this function.
argv = 'here are "two words"'.shellsplit argv #=> ["here", "are", "two words"]
Raises a TypeError to prevent cloning.
Returns a topologically sorted array of nodes. The array is sorted from children to parents, i.e. the first element has no child and the last node has no parent.
If there is a cycle, TSort::Cyclic is raised.
class G include TSort def initialize(g) @g = g end def tsort_each_child(n, &b) @g[n].each(&b) end def tsort_each_node(&b) @g.each_key(&b) end end graph = G.new({1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}) p graph.tsort #=> [4, 2, 3, 1] graph = G.new({1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}) p graph.tsort # raises TSort::Cyclic
Returns a topologically sorted array of nodes. The array is sorted from children to parents, i.e. the first element has no child and the last node has no parent.
The graph is represented by each_node and each_child. each_node should have call method which yields for each node in the graph. each_child should have call method which takes a node argument and yields for each child node.
If there is a cycle, TSort::Cyclic is raised.
g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]} each_node = lambda {|&b| g.each_key(&b) } each_child = lambda {|n, &b| g[n].each(&b) } p TSort.tsort(each_node, each_child) #=> [4, 2, 3, 1] g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]} each_node = lambda {|&b| g.each_key(&b) } each_child = lambda {|n, &b| g[n].each(&b) } p TSort.tsort(each_node, each_child) # raises TSort::Cyclic
Returns the principal (non-negative) square root of x.
Domain: [0, INFINITY].
Range: [0, INFINITY].
Examples:
sqrt(0.0) # => 0.0 sqrt(0.5) # => 0.7071067811865476 sqrt(1.0) # => 1.0 sqrt(2.0) # => 1.4142135623730951 sqrt(4.0) # => 2.0 sqrt(9.0) # => 3.0 sqrt(INFINITY) # => Infinity