Similar to read, but raises EOFError at end of string instead of returning nil, as well as IO#sysread does.
Executes the block for every line in the stream where lines are separated by eol.
See also gets
Reads a one-character string from the stream. Raises an EOFError at end of file.
Generate a Checkbox Input element as a string.
The attributes of the element can be specified as three arguments, name, value, and checked. checked is a boolean value; if true, the CHECKED attribute will be included in the element.
Alternatively, the attributes can be specified as a hash.
checkbox("name") # = checkbox("NAME" => "name") checkbox("name", "value") # = checkbox("NAME" => "name", "VALUE" => "value") checkbox("name", "value", true) # = checkbox("NAME" => "name", "VALUE" => "value", "CHECKED" => true)
With a block, returns the string value for key if it exists; otherwise returns the value of the block; ignores the default_val; see Fields:
res = Net::HTTP.get_response(hostname, '/todos/1') # Field exists; block not called. res.fetch('Connection') do |value| fail 'Cannot happen' end # => "keep-alive" # Field does not exist; block called. res.fetch('Nosuch') do |value| value.downcase end # => "nosuch"
With no block, returns the string value for key if it exists; otherwise, returns default_val if it was given; otherwise raises an exception:
res.fetch('Connection', 'Foo') # => "keep-alive" res.fetch('Nosuch', 'Foo') # => "Foo" res.fetch('Nosuch') # Raises KeyError.
Returns true if field 'Transfer-Encoding' exists and has value 'chunked', false otherwise; see Transfer-Encoding response header:
res = Net::HTTP.get_response(hostname, '/todos/1') res['Transfer-Encoding'] # => "chunked" res.chunked? # => true
returns a charset parameter in Content-Type field. It is downcased for canonicalization.
If charset parameter is not given but a block is given, the block is called and its result is returned. It can be used to guess charset.
If charset parameter and block is not given, nil is returned except text type. In that case, “utf-8” is returned as defined by RFC6838 4.2.1
Generate a string that randomly draws from a source array of characters.
The argument source specifies the array of characters from which to generate the string. The argument n specifies the length, in characters, of the string to be generated.
The result may contain whatever characters are in the source array.
require 'random/formatter' prng.choose([*'l'..'r'], 16) #=> "lmrqpoonmmlqlron" prng.choose([*'0'..'9'], 5) #=> "27309"
Switch the effective and real user IDs of the current process. If a block is given, the user IDs will be switched back after the block is executed. Returns the new effective user ID if called without a block, and the return value of the block if one is given.
Switch the effective and real group IDs of the current process. If a block is given, the group IDs will be switched back after the block is executed. Returns the new effective group ID if called without a block, and the return value of the block if one is given.
Iterates over array indexes.
When a block given, passes each successive array index to the block; returns self:
a = [:foo, 'bar', 2] a.each_index {|index| puts "#{index} #{a[index]}" }
Output:
0 foo 1 bar 2 2
Allows the array to be modified during iteration:
a = [:foo, 'bar', 2] a.each_index {|index| puts index; a.clear if index > 0 }
Output:
0 1
When no block given, returns a new Enumerator:
a = [:foo, 'bar', 2] e = a.each_index e # => #<Enumerator: [:foo, "bar", 2]:each_index> a1 = e.each {|index| puts "#{index} #{a[index]}"}
Output:
0 foo 1 bar 2 2
Related: each, reverse_each.
Iterates backwards over array elements.
When a block given, passes, in reverse order, each element to the block; returns self:
a = [:foo, 'bar', 2] a.reverse_each {|element| puts "#{element.class} #{element}" }
Output:
Integer 2 String bar Symbol foo
Allows the array to be modified during iteration:
a = [:foo, 'bar', 2] a.reverse_each {|element| puts element; a.clear if element.to_s.start_with?('b') }
Output:
2 bar
When no block given, returns a new Enumerator:
a = [:foo, 'bar', 2] e = a.reverse_each e # => #<Enumerator: [:foo, "bar", 2]:reverse_each> a1 = e.each {|element| puts "#{element.class} #{element}" }
Output:
Integer 2 String bar Symbol foo
Related: each, each_index.
Searches self as described at method bsearch, but returns the index of the found element instead of the element itself.
Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.
"Koala".intern #=> :Koala s = 'cat'.to_sym #=> :cat s == :cat #=> true s = '@cat'.to_sym #=> :@cat s == :@cat #=> true
This can also be used to create symbols that cannot be represented using the :xxx notation.
'cat and dog'.to_sym #=> :"cat and dog"
With a block given, forms the substrings (“lines”) that are the result of splitting self at each occurrence of the given line separator line_sep; passes each line to the block; returns self:
s = <<~EOT This is the first line. This is line two. This is line four. This is line five. EOT s.each_line {|line| p line }
Output:
"This is the first line.\n" "This is line two.\n" "\n" "This is line four.\n" "This is line five.\n"
With a different line_sep:
s.each_line(' is ') {|line| p line }
Output:
"This is " "the first line.\nThis is " "line two.\n\nThis is " "line four.\nThis is " "line five.\n"
With chomp as true, removes the trailing line_sep from each line:
s.each_line(chomp: true) {|line| p line }
Output:
"This is the first line." "This is line two." "" "This is line four." "This is line five."
With an empty string as line_sep, forms and passes “paragraphs” by splitting at each occurrence of two or more newlines:
s.each_line('') {|line| p line }
Output:
"This is the first line.\nThis is line two.\n\n" "This is line four.\nThis is line five.\n"
With no block given, returns an enumerator.
Calls the given block with each successive byte from self; returns self:
'hello'.each_byte {|byte| print byte, ' ' } print "\n" 'тест'.each_byte {|byte| print byte, ' ' } print "\n" 'こんにちは'.each_byte {|byte| print byte, ' ' } print "\n"
Output:
104 101 108 108 111 209 130 208 181 209 129 209 130 227 129 147 227 130 147 227 129 171 227 129 161 227 129 175
Returns an enumerator if no block is given.
Calls the given block with each successive codepoint from self; each codepoint is the integer value for a character; returns self:
'hello'.each_codepoint {|codepoint| print codepoint, ' ' } print "\n" 'тест'.each_codepoint {|codepoint| print codepoint, ' ' } print "\n" 'こんにちは'.each_codepoint {|codepoint| print codepoint, ' ' } print "\n"
Output:
104 101 108 108 111 1090 1077 1089 1090 12371 12435 12395 12385 12399
Returns an enumerator if no block is given.
Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking fibers (created by Fiber.new with blocking: false, or by Fiber.schedule) call that scheduler’s hook methods on potentially blocking operations, and the current thread will call scheduler’s close method on finalization (allowing the scheduler to properly manage all non-finished fibers).
scheduler can be an object of any class corresponding to Fiber::Scheduler. Its implementation is up to the user.
See also the “Non-blocking fibers” section in class docs.
Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler if and only if the current fiber is non-blocking.
Returns the locale charmap name. It returns nil if no appropriate information.
Debian GNU/Linux LANG=C Encoding.locale_charmap #=> "ANSI_X3.4-1968" LANG=ja_JP.EUC-JP Encoding.locale_charmap #=> "EUC-JP" SunOS 5 LANG=C Encoding.locale_charmap #=> "646" LANG=ja Encoding.locale_charmap #=> "eucJP"
The result is highly platform dependent. So Encoding.find(Encoding.locale_charmap) may cause an error. If you need some encoding object even for unknown locale, Encoding.find(“locale”) can be used.
Return the accept character set for all new CGI instances.