Returns true if sym
starts with one of the prefixes
given. Each of the prefixes
should be a String
or a Regexp
.
:hello.start_with?("hell") #=> true :hello.start_with?(/H/i) #=> true # returns true if one of the prefixes matches. :hello.start_with?("heaven", "hell") #=> true :hello.start_with?("heaven", "paradise") #=> false
Returns true if sym
ends with one of the suffixes
given.
:hello.end_with?("ello") #=> true # returns true if one of the +suffixes+ matches. :hello.end_with?("heaven", "ello") #=> true :hello.end_with?("heaven", "paradise") #=> false
Returns true if this class can be used to create an instance from a serialised JSON
string. The class has to implement a class method json_create that expects a hash as first parameter. The hash should include the required data.
Returns an Array
of values corresponding to the given keys.
Iterates over each key-value pair in the database.
If no block is given, returns an Enumerator
.
creates an Addrinfo
object from the arguments.
The arguments are interpreted as similar to self.
Addrinfo.tcp("0.0.0.0", 4649).family_addrinfo("www.ruby-lang.org", 80) #=> #<Addrinfo: 221.186.184.68:80 TCP (www.ruby-lang.org:80)> Addrinfo.unix("/tmp/sock").family_addrinfo("/tmp/sock2") #=> #<Addrinfo: /tmp/sock2 SOCK_STREAM>
creates a new Socket
connected to the address of local_addrinfo
.
If local_addrinfo is nil, the address of the socket is not bound.
The timeout specify the seconds for timeout. Errno::ETIMEDOUT is raised when timeout occur.
If a block is given the created socket is yielded for each address.
Returns the IP address and port number as 2-element array.
Addrinfo.tcp("127.0.0.1", 80).ip_unpack #=> ["127.0.0.1", 80] Addrinfo.tcp("::1", 80).ip_unpack #=> ["::1", 80]
Returns true for IPv4 private address (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). It returns false otherwise.
Returns the Encoding
object that represents the encoding of the file. If the stream is write mode and no encoding is specified, returns nil
.
Returns the Encoding
of the internal string if conversion is specified. Otherwise returns nil
.
Returns the size of the most recent match (see matched
), or nil
if there was no recent match.
s = StringScanner.new('test string') s.check /\w+/ # -> "test" s.matched_size # -> 4 s.check /\d+/ # -> nil s.matched_size # -> nil
Returns the pre-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Returns the post-match
(in the regular expression sense) of the last scan.s = StringScanner.new('test string') s.scan(/\w+/) # -> "test" s.scan(/\s+/) # -> " " s.pre_match # -> "test" s.post_match # -> "string"
Returns the subgroups in the most recent match at the given indices. If nothing was priorly matched, it returns nil.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.scan(/(\w+) (\w+) (\d+) /) # -> "Fri Dec 12 " s.values_at 0, -1, 5, 2 # -> ["Fri Dec 12 ", "12", nil, "Dec"] s.scan(/(\w+) (\w+) (\d+) /) # -> nil s.values_at 0, -1, 5, 2 # -> nil
Creates GUID.
WIN32OLE.create_guid # => {1CB530F1-F6B1-404D-BCE6-1959BF91F4A8}
Translates and dispatches Windows message.
Calls block once for each key in hsh, passing the key-value pair as parameters.
If no block is given, an enumerator is returned instead.
h = { "a" => 100, "b" => 200 } h.each {|key, value| puts "#{key} is #{value}" }
produces:
a is 100 b is 200
Return an array containing the values associated with the given keys. Also see Hash.select
.
h = { "cat" => "feline", "dog" => "canine", "cow" => "bovine" } h.values_at("cow", "cat") #=> ["bovine", "feline"]
Yields each environment variable name and its value as a 2-element Array:
h = {} ENV.each_pair { |name, value| h[name] = value } # => ENV h # => {"bar"=>"1", "foo"=>"0"}
Returns an Enumerator
if no block given:
h = {} e = ENV.each_pair # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_pair> e.each { |name, value| h[name] = value } # => ENV h # => {"bar"=>"1", "foo"=>"0"}
Returns an array containing the environment variable values associated with the given names. See also ENV.select
.
Returns the external encoding for files read from ARGF
as an Encoding
object. The external encoding is the encoding of the text as stored in a file. Contrast with ARGF.internal_encoding
, which is the encoding used to represent this text within Ruby.
To set the external encoding use ARGF.set_encoding
.
For example:
ARGF.external_encoding #=> #<Encoding:UTF-8>
Returns the internal encoding for strings read from ARGF
as an Encoding
object.
If ARGF.set_encoding
has been called with two encoding names, the second is returned. Otherwise, if Encoding.default_external
has been set, that value is returned. Failing that, if a default external encoding was specified on the command-line, that value is used. If the encoding is unknown, nil
is returned.