Returns true for IPv4 multicast address (224.0.0.0/4). It returns false otherwise.
Returns true for IPv6 multicast address (ff00::/8). It returns false otherwise.
Returns true for IPv6 link local address (fe80::/10). It returns false otherwise.
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an accepted TCPSocket for the incoming connection.
require 'socket' serv = TCPServer.new(2202) begin # emulate blocking accept sock = serv.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select([serv]) retry end # sock is an accepted socket.
Refer to Socket#accept for the exceptions that may be thrown if the call to TCPServer#accept_nonblock fails.
TCPServer#accept_nonblock may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED, Errno::EPROTO, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.
By specifying a keyword argument exception to false, you can indicate that accept_nonblock should not raise an IO::WaitReadable exception, but return the symbol :wait_readable instead.
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an accepted UNIXSocket for the incoming connection.
require 'socket' serv = UNIXServer.new("/tmp/sock") begin # emulate blocking accept sock = serv.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select([serv]) retry end # sock is an accepted socket.
Refer to Socket#accept for the exceptions that may be thrown if the call to UNIXServer#accept_nonblock fails.
UNIXServer#accept_nonblock may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED or Errno::EPROTO, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.
By specifying a keyword argument exception to false, you can indicate that accept_nonblock should not raise an IO::WaitReadable exception, but return the symbol :wait_readable instead.
Calls the block with each remaining line read from the stream; does nothing if already at end-of-file; returns self. See Line IO.
StringIO#each is an alias for StringIO#each_line.
Duplicates a StringScanner object.
Returns the WIN32OLE_TYPELIB object. The object represents the type library which contains the WIN32OLE object.
excel = WIN32OLE.new('Excel.Application') tlib = excel.ole_typelib puts tlib.name # -> 'Microsoft Excel 9.0 Object Library'
Evaluates a string containing Ruby source code, or the given block, within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj’s instance variables and private methods.
When instance_eval is given a block, obj is also passed in as the block’s only argument.
When instance_eval is given a String, the optional second and third parameters supply a filename and starting line number that are used when reporting compilation errors.
class KlassWithSecret def initialize @secret = 99 end private def the_secret "Ssssh! The secret is #{@secret}." end end k = KlassWithSecret.new k.instance_eval { @secret } #=> 99 k.instance_eval { the_secret } #=> "Ssssh! The secret is 99." k.instance_eval {|obj| obj == self } #=> true
Executes the given block within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj’s instance variables. Arguments are passed as block parameters.
class KlassWithSecret def initialize @secret = 99 end end k = KlassWithSecret.new k.instance_exec(5) {|x| @secret+x } #=> 104
Replaces the entire contents of self with the contents of other_hash; returns self:
h = {foo: 0, bar: 1, baz: 2} h.replace({bat: 3, bam: 4}) # => {:bat=>3, :bam=>4}
Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is an Integer specifying the maximum length of each line; longer lines will be split according to this limit.
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 line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename of the current line and line number of the whole input, respectively.
For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:
ARGF.each_line do |line| puts ARGF.filename if ARGF.file.lineno == 1 puts "#{ARGF.file.lineno}: #{line}" end
While the following code prints only the first file’s name at first, and the contents with line number counted through all named files.
ARGF.each_line do |line| puts ARGF.filename if ARGF.lineno == 1 puts "#{ARGF.lineno}: #{line}" end
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 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 Regexp used to identify comment lines; used for parsing; see {Option skip_lines}:
CSV.new('').skip_lines # => nil
Returns the value that determines whether all output fields are to be quoted; used for generating; see {Option force_quotes}:
CSV.new('').force_quotes? # => false
Returns the value that determines whether illegal input is to be handled; used for parsing; see {Option liberal_parsing}:
CSV.new('').liberal_parsing? # => false
Returns true if the ipaddr is a link-local address. IPv4 addresses in 169.254.0.0/16 reserved by RFC 3927 and Link-Local IPv6 Unicast Addresses in fe80::/10 reserved by RFC 4291 are considered link-local.
Returns the Ruby source filename and line number of the binding object.