Removes all hash entries; returns self.
Deletes the environment variable with name if it exists and returns its value:
ENV['foo'] = '0' ENV.delete('foo') # => '0'
If a block is not given and the named environment variable does not exist, returns nil.
If a block given and the environment variable does not exist, yields name to the block and returns the value of the block:
ENV.delete('foo') { |name| name * 2 } # => "foofoo"
If a block given and the environment variable exists, deletes the environment variable and returns its value (ignoring the block):
ENV['foo'] = '0' ENV.delete('foo') { |name| raise 'ignored' } # => "0"
Raises an exception if name is invalid. See Invalid Names and Values.
Removes every environment variable; returns ENV:
ENV.replace('foo' => '0', 'bar' => '1') ENV.size # => 2 ENV.clear # => ENV ENV.size # => 0
Returns the count of environment variables:
ENV.replace('foo' => '0', 'bar' => '1') ENV.length # => 2 ENV.size # => 2
Returns an integer representing the numeric file descriptor for the current file. Raises an ArgumentError if there isn’t a current file.
ARGF.fileno #=> 3
Returns the current filename. “-” is returned when the current file is STDIN.
For example:
$ echo "foo" > foo $ echo "bar" > bar $ echo "glark" > glark $ ruby argf.rb foo bar glark ARGF.filename #=> "foo" ARGF.read(5) #=> "foo\nb" ARGF.filename #=> "bar" ARGF.skip ARGF.filename #=> "glark"
Returns the current file as an IO or File object. $stdin is returned when the current file is STDIN.
For example:
$ echo "foo" > foo $ echo "bar" > bar $ ruby argf.rb foo bar ARGF.file #=> #<File:foo> ARGF.read(5) #=> "foo\nb" ARGF.file #=> #<File:bar>
Calls CSV.read with source, options, and certain default options:
headers: true
converters: :numeric
header_converters: :symbol
Returns a CSV::Table object.
Example:
string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string) CSV.table(path) # => #<CSV::Table mode:col_or_row row_count:4>
Returns the methods available to this delegate object as the union of this object’s and _getobj_ methods.
Executes the generated ERB code to produce a completed template, returning the results of that code. (See ERB::new for details on how this process can be affected by safe_level.)
b accepts a Binding object which is used to set the context of code evaluation.
Release code
Removes the last List.
Returns the number of elements in the match array.
m = /(.)(.)(\d+)(\d)/.match("THX1138.") m.length #=> 5 m.size #=> 5
This says “you can break a line here if necessary”, and a width-column text sep is inserted if a line is not broken at the point.
If sep is not specified, “ ” is used.
If width is not specified, sep.length is used. You will have to specify this when sep is a multibyte character, for example.
Removes an object hierarchy from the data store, by name.
WARNING: This method is only valid in a PStore#transaction and it cannot be read-only. It will raise PStore::Error if called at any other time.
Sets default task values
Checks if the object is shareable by ractors.
Ractor.shareable?(1) #=> true -- numbers and other immutable basic values are frozen Ractor.shareable?('foo') #=> false, unless the string is frozen due to # freeze_string_literals: true Ractor.shareable?('foo'.freeze) #=> true
See also the “Shareable and unshareable objects” section in the Ractor class docs.
Activates the trace.
Returns true if trace was enabled. Returns false if trace was disabled.
trace.enabled? #=> false trace.enable #=> false (previous state) # trace is enabled trace.enabled? #=> true trace.enable #=> true (previous state) # trace is still enabled
If a block is given, the trace will only be enabled within the scope of the block.
trace.enabled? #=> false trace.enable do trace.enabled? # only enabled for this block end trace.enabled? #=> false
target, target_line and target_thread parameters are used to limit tracing only to specified code objects. target should be a code object for which RubyVM::InstructionSequence.of will return an instruction sequence.
t = TracePoint.new(:line) { |tp| p tp } def m1 p 1 end def m2 p 2 end t.enable(target: method(:m1)) m1 # prints #<TracePoint:line test.rb:4 in `m1'> m2 # prints nothing
Note: You cannot access event hooks within the enable block.
trace.enable { p tp.lineno } #=> RuntimeError: access from outside
Deactivates the trace
Return true if trace was enabled. Return false if trace was disabled.
trace.enabled? #=> true trace.disable #=> true (previous status) trace.enabled? #=> false trace.disable #=> false
If a block is given, the trace will only be disable within the scope of the block.
trace.enabled? #=> true trace.disable do trace.enabled? # only disabled for this block end trace.enabled? #=> true
Note: You cannot access event hooks within the block.
trace.disable { p tp.lineno } #=> RuntimeError: access from outside
The current status of the trace
Returns x+i*y;
Complex(1, 2) #=> (1+2i) Complex('1+2i') #=> (1+2i) Complex(nil) #=> TypeError Complex(1, nil) #=> TypeError Complex(1, nil, exception: false) #=> nil Complex('1+2', exception: false) #=> nil
Syntax of string form:
string form = extra spaces , complex , extra spaces ;
complex = real part | [ sign ] , imaginary part
| real part , sign , imaginary part
| rational , "@" , rational ;
real part = rational ;
imaginary part = imaginary unit | unsigned rational , imaginary unit ;
rational = [ sign ] , unsigned rational ;
unsigned rational = numerator | numerator , "/" , denominator ;
numerator = integer part | fractional part | integer part , fractional part ;
denominator = digits ;
integer part = digits ;
fractional part = "." , digits , [ ( "e" | "E" ) , [ sign ] , digits ] ;
imaginary unit = "i" | "I" | "j" | "J" ;
sign = "-" | "+" ;
digits = digit , { digit | "_" , digit };
digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
extra spaces = ? \s* ? ;
See String#to_c.