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 IO object representing the current file. This will be a File object unless the current file is a stream such as STDIN.
For example:
ARGF.to_io #=> #<File:glark.txt> ARGF.to_io #=> #<IO:<STDIN>>
Iterates over each character of each file in ARGF.
This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last character of the first file has been returned, the first character of the second file is returned. The ARGF.filename method can be used to determine the name of the file in which the current character appears.
If no block is given, an enumerator is returned instead.
Reads at most maxlen bytes from the ARGF stream in non-blocking mode.
Returns the file extension appended to the names of backup copies of modified files under in-place edit mode. This value can be set using ARGF.inplace_mode= or passing the -i switch to the Ruby binary.
Sets the filename extension for in-place editing mode to the given String. The backup copy of each file being edited has this value appended to its filename.
For example:
$ ruby argf.rb file.txt
ARGF.inplace_mode = '.bak'
ARGF.each_line do |line|
print line.sub("foo","bar")
end
First, file.txt.bak is created as a backup copy of file.txt. Then, each line of file.txt has the first occurrence of “foo” replaced with “bar”.
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.
If single argument is specified, strings read from ARGF are tagged with the encoding specified.
If two encoding names separated by a colon are given, e.g. “ascii:utf-8”, the read string is converted from the first encoding (external encoding) to the second encoding (internal encoding), then tagged with the second encoding.
If two arguments are specified, they must be encoding objects or encoding names. Again, the first specifies the external encoding; the second specifies the internal encoding.
If the external encoding and the internal encoding are specified, the optional Hash argument can be used to adjust the conversion process. The structure of this hash is explained in the String#encode documentation.
For example:
ARGF.set_encoding('ascii') # Tag the input as US-ASCII text ARGF.set_encoding(Encoding::UTF_8) # Tag the input as UTF-8 text ARGF.set_encoding('utf-8','ascii') # Transcode the input from US-ASCII # to UTF-8.
Creates a new compiler for ERB. See ERB::Compiler.new for details
Returns a new binding each time near TOPLEVEL_BINDING for runs that do not specify a binding.
Returns a string containing the IP address representation with prefix.
Returns a json string containing the IP address representation.
Returns true if the ipaddr is an IPv4-compatible IPv6 address.
Returns a new ipaddr built by converting the native IPv4 address into an IPv4-compatible IPv6 address.
Returns the wildcard mask in string format e.g. 0.0.255.255
Returns the IPv6 zone identifier, if present. Raises InvalidAddressError if not an IPv6 address.
Returns the IPv6 zone identifier, if present. Raises InvalidAddressError if not an IPv6 address.
Returns a hash of the name/value pairs, to use in pattern matching.
Measure = Data.define(:amount, :unit) distance = Measure[10, 'km'] distance.deconstruct_keys(nil) #=> {:amount=>10, :unit=>"km"} distance.deconstruct_keys([:amount]) #=> {:amount=>10} # usage case distance in amount:, unit: 'km' # calls #deconstruct_keys underneath puts "It is #{amount} kilometers away" else puts "Don't know how to handle it" end # prints "It is 10 kilometers away"
Or, with checking the class, too:
case distance in Measure(amount:, unit: 'km') puts "It is #{amount} kilometers away" # ... end
Returns a hash of the named captures; each key is a capture name; each value is its captured string or nil:
m = /(?<foo>.)(.)(?<bar>.+)/.match("hoge") # => #<MatchData "hoge" foo:"h" bar:"ge"> m.named_captures # => {"foo"=>"h", "bar"=>"ge"} m = /(?<a>.)(?<b>.)/.match("01") # => #<MatchData "01" a:"0" b:"1"> m.named_captures #=> {"a" => "0", "b" => "1"} m = /(?<a>.)(?<b>.)?/.match("0") # => #<MatchData "0" a:"0" b:nil> m.named_captures #=> {"a" => "0", "b" => nil} m = /(?<a>.)(?<a>.)/.match("01") # => #<MatchData "01" a:"0" a:"1"> m.named_captures #=> {"a" => "1"}
If keyword argument symbolize_names is given a true value, the keys in the resulting hash are Symbols:
m = /(?<a>.)(?<a>.)/.match("01") # => #<MatchData "01" a:"0" a:"1"> m.named_captures(symbolize_names: true) #=> {:a => "1"}
Returns a hash of the named captures for the given names.
m = /(?<hours>\d{2}):(?<minutes>\d{2}):(?<seconds>\d{2})/.match("18:37:22") m.deconstruct_keys([:hours, :minutes]) # => {:hours => "18", :minutes => "37"} m.deconstruct_keys(nil) # => {:hours => "18", :minutes => "37", :seconds => "22"}
Returns an empty hash if no named captures were defined:
m = /(\d{2}):(\d{2}):(\d{2})/.match("18:37:22") m.deconstruct_keys(nil) # => {}
Returns the names of the binding’s local variables as symbols.
def foo a = 1 2.times do |n| binding.local_variables #=> [:a, :n] end end
This method is the short version of the following code:
binding.eval("local_variables")
Returns a Method of superclass which would be called when super is used or nil if there is no method on superclass.