Returns the size of the most recent match in bytes, or nil if there was no recent match. This is different than matched.size, which will return the size in characters.
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}
Hash#each is an alias for Hash#each_pair.
Calls the given block with each key-value pair; returns self:
h = {foo: 0, bar: 1, baz: 2} h.each_pair {|key, value| puts "#{key}: #{value}"} # => {:foo=>0, :bar=>1, :baz=>2}
Output:
foo: 0 bar: 1 baz: 2
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.each_pair # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:each_pair> h1 = e.each {|key, value| puts "#{key}: #{value}"} h1 # => {:foo=>0, :bar=>1, :baz=>2}
Output:
foo: 0 bar: 1 baz: 2
Returns a new Array containing values for the given keys:
h = {foo: 0, bar: 1, baz: 2} h.values_at(:baz, :foo) # => [2, 0]
The default values are returned for any keys that are not found:
h.values_at(:hello, :foo) # => [nil, 0]
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:
ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2') ENV.values_at('foo', 'baz') # => ["0", "2"]
Returns nil in the Array for each name that is not an ENV name:
ENV.values_at('foo', 'bat', 'bar', 'bam') # => ["0", nil, "1", nil]
Returns an empty Array if no names given.
Raises an exception if any name is invalid. See Invalid Names and Values.
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.
Returns the String created by generating CSV from ary using the specified options.
Argument ary must be an Array.
Special options:
Option :row_sep defaults to "\n"> on Ruby 3.0 or later and <tt>$INPUT_RECORD_SEPARATOR ($/) otherwise.:
$INPUT_RECORD_SEPARATOR # => "\n"
This method accepts an additional option, :encoding, which sets the base Encoding for the output. This method will try to guess your Encoding from the first non-nil field in row, if possible, but you may need to use this parameter as a backup plan.
For other options, see Options for Generating.
Returns the String generated from an Array:
CSV.generate_line(['foo', '0']) # => "foo,0\n"
Raises an exception if ary is not an Array:
# Raises NoMethodError (undefined method `find' for :foo:Symbol) CSV.generate_line(:foo)
Returns the String created by generating CSV from using the specified options.
Argument rows must be an Array of row. Row is Array of String or CSV::Row.
Special options:
Option :row_sep defaults to "\n" on Ruby 3.0 or later and $INPUT_RECORD_SEPARATOR ($/) otherwise.:
$INPUT_RECORD_SEPARATOR # => "\n"
This method accepts an additional option, :encoding, which sets the base Encoding for the output. This method will try to guess your Encoding from the first non-nil field in row, if possible, but you may need to use this parameter as a backup plan.
For other options, see Options for Generating.
Returns the String generated from an
CSV.generate_lines([['foo', '0'], ['bar', '1'], ['baz', '2']]) # => "foo,0\nbar,1\nbaz,2\n"
Raises an exception
# Raises NoMethodError (undefined method `each' for :foo:Symbol) CSV.generate_lines(:foo)
Returns the data created by parsing the first line of string or io using the specified options.
Argument string should be a String object; it will be put into a new StringIO object positioned at the beginning.
Argument io should be an IO object that is:
Open for reading; on return, the IO object will be closed.
Positioned at the beginning. To position at the end, for appending, use method CSV.generate. For any other positioning, pass a preset StringIO object instead.
Argument options: see Options for Parsing
headers Without option headers, returns the first row as a new Array.
These examples assume prior execution of:
string = "foo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string)
Parse the first line from a String object:
CSV.parse_line(string) # => ["foo", "0"]
Parse the first line from a File object:
File.open(path) do |file| CSV.parse_line(file) # => ["foo", "0"] end # => ["foo", "0"]
Returns nil if the argument is an empty String:
CSV.parse_line('') # => nil
headers With {option headers}, returns the first row as a CSV::Row object.
These examples assume prior execution of:
string = "Name,Count\nfoo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string)
Parse the first line from a String object:
CSV.parse_line(string, headers: true) # => #<CSV::Row "Name":"foo" "Count":"0">
Parse the first line from a File object:
File.open(path) do |file| CSV.parse_line(file, headers: true) end # => #<CSV::Row "Name":"foo" "Count":"0">
Raises an exception if the argument is nil:
# Raises ArgumentError (Cannot parse nil as CSV): CSV.parse_line(nil)
Returns the value that determines whether illegal input is to be handled; used for parsing; see {Option liberal_parsing}:
CSV.new('').liberal_parsing? # => false
Return the appropriate error message in POSIX-defined format. If no error has occurred, returns nil.
Returns a string for DNS reverse lookup compatible with RFC3172.
Returns the Ruby source filename and line number of the binding object.
Returns the usable width for out. As the width of out:
If out is assigned to a tty device, its width is used.
Otherwise, or it could not get the value, the COLUMN environment variable is assumed to be set to the width.
If COLUMN is not set to a non-zero number, 80 is assumed.
And finally, returns the above width value - 1.
This -1 is for Windows command prompt, which moves the cursor to the next line if it reaches the last column.
Returns match and captures at the given indexes, which may include any mixture of:
Integers.
Ranges.
Names (strings and symbols).
Examples:
m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m.values_at(0, 2, -2) # => ["HX1138", "X", "113"] m.values_at(1..2, -1) # => ["H", "X", "8"] m = /(?<a>\d+) *(?<op>[+\-*\/]) *(?<b>\d+)/.match("1 + 2") # => #<MatchData "1 + 2" a:"1" op:"+" b:"2"> m.values_at(0, 1..2, :a, :b, :op) # => ["1 + 2", "1", "+", "1", "2", "+"]
Returns the substring of the target string from its beginning up to the first match in self (that is, self[0]); equivalent to regexp global variable $`:
m = /(.)(.)(\d+)(\d)/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.pre_match # => "T"
Related: MatchData#post_match.