Installs the gem dep_or_name and all its dependencies. Returns an Array of installed gem specifications.
If the :prerelease option is set and there is a prerelease for dep_or_name the prerelease version will be installed.
Unless explicitly specified as a prerelease dependency, prerelease gems that dep_or_name depend on will not be installed.
If c-1.a depends on b-1 and a-1.a and there is a gem b-1.a available then c-1.a, b-1 and a-1.a will be installed. b-1.a will need to be installed separately.
Installs the gem and returns a loaded Gem::Specification for the installed gem.
The gem will be installed with the following structure:
@gem_home/ cache/<gem-version>.gem #=> a cached copy of the installed gem gems/<gem-version>/... #=> extracted files specifications/<gem-version>.gemspec #=> the Gem::Specification
Installs gems for this RequestSet using the Gem::Installer options.
If a block is given an activation request and installer are yielded. The installer will be nil if a gem matching the request was already installed.
Performs the uninstall of the gem. This removes the spec, the Gem directory, and the cached .gem file.
See also Enumerable#all?
Returns true if all bits of int & mask are 1.
Returns a copy of str with the first character converted to uppercase and the remainder to lowercase.
See String#downcase for meaning of options and use with different encodings.
"hello".capitalize #=> "Hello" "HELLO".capitalize #=> "Hello" "123ABC".capitalize #=> "123abc"
Modifies str by converting the first character to uppercase and the remainder to lowercase. Returns nil if no changes are made. There is an exception for modern Georgian (mkhedruli/MTAVRULI), where the result is the same as for String#downcase, to avoid mixed case.
See String#downcase for meaning of options and use with different encodings.
a = "hello" a.capitalize! #=> "Hello" a #=> "Hello" a.capitalize! #=> nil
Invokes the continuation. The program continues from the end of the callcc block. If no arguments are given, the original callcc returns nil. If one argument is given, callcc returns it. Otherwise, an array containing args is returned.
callcc {|cont| cont.call } #=> nil callcc {|cont| cont.call 1 } #=> 1 callcc {|cont| cont.call 1, 2, 3 } #=> [1, 2, 3]
Same as sym.to_s.capitalize.intern.
Allocates space for a new object of class’s class and does not call initialize on the new instance. The returned object must be an instance of class.
klass = Class.new do def initialize(*args) @initialized = true end def initialized? @initialized || false end end klass.allocate.initialized? #=> false
Returns true iff the current severity level allows for the printing of FATAL messages.
Sets the severity to FATAL.
Invokes the block, setting the block’s parameters to the values in params using something close to method calling semantics. Returns the value of the last expression evaluated in the block.
a_proc = Proc.new {|scalar, *values| values.map {|value| value*scalar } } a_proc.call(9, 1, 2, 3) #=> [9, 18, 27] a_proc[9, 1, 2, 3] #=> [9, 18, 27] a_proc.(9, 1, 2, 3) #=> [9, 18, 27] a_proc.yield(9, 1, 2, 3) #=> [9, 18, 27]
Note that prc.() invokes prc.call() with the parameters given. It’s syntactic sugar to hide “call”.
For procs created using lambda or ->() an error is generated if the wrong number of parameters are passed to the proc. For procs created using Proc.new or Kernel.proc, extra parameters are silently discarded and missing parameters are set to nil.
a_proc = proc {|a,b| [a,b] } a_proc.call(1) #=> [1, nil] a_proc = lambda {|a,b| [a,b] } a_proc.call(1) # ArgumentError: wrong number of arguments (given 1, expected 2)
See also Proc#lambda?.
Invokes the meth with the specified arguments, returning the method’s return value.
m = 12.method("+") m.call(3) #=> 15 m.call(20) #=> 32
Generates a Continuation object, which it passes to the associated block. You need to require 'continuation' before using this method. Performing a cont.call will cause the callcc to return (as will falling through the end of the block). The value returned by the callcc is the value of the block, or the value passed to cont.call. See class Continuation for more details. Also see Kernel#throw for an alternative mechanism for unwinding a call stack.
Returns the called name of the current method as a Symbol. If called outside of a method, it returns nil.
Calls the operating system function identified by num and returns the result of the function or raises SystemCallError if it failed.
Arguments for the function can follow num. They must be either String objects or Integer objects. A String object is passed as a pointer to the byte sequence. An Integer object is passed as an integer whose bit size is same as a pointer. Up to nine parameters may be passed.
The function identified by num is system dependent. On some Unix systems, the numbers may be obtained from a header file called syscall.h.
syscall 4, 1, "hello\n", 6 # '4' is write(2) on our box
produces:
hello
Calling syscall on a platform which does not have any way to an arbitrary system function just fails with NotImplementedError.
Note: syscall is essentially unsafe and unportable. Feel free to shoot your foot. The DL (Fiddle) library is preferred for safer and a bit more portable programming.
Returns the current execution stack—an array containing strings in the form file:line or file:line: in `method'.
The optional start parameter determines the number of initial stack entries to omit from the top of the stack.
A second optional length parameter can be used to limit how many entries are returned from the stack.
Returns nil if start is greater than the size of current execution stack.
Optionally you can pass a range, which will return an array containing the entries within the specified range.
def a(skip) caller(skip) end def b(skip) a(skip) end def c(skip) b(skip) end c(0) #=> ["prog:2:in `a'", "prog:5:in `b'", "prog:8:in `c'", "prog:10:in `<main>'"] c(1) #=> ["prog:5:in `b'", "prog:8:in `c'", "prog:11:in `<main>'"] c(2) #=> ["prog:8:in `c'", "prog:12:in `<main>'"] c(3) #=> ["prog:13:in `<main>'"] c(4) #=> [] c(5) #=> nil
Passes each element of the collection to the given block. The method returns true if the block never returns false or nil. If the block is not given, Ruby adds an implicit block of { |obj| obj } which will cause all? to return true when none of the collection members are false or nil.
If instead a pattern is supplied, the method returns whether pattern === element for every collection member.
%w[ant bear cat].all? { |word| word.length >= 3 } #=> true %w[ant bear cat].all? { |word| word.length >= 4 } #=> false %w[ant bear cat].all?(/t/) #=> false [1, 2i, 3.14].all?(Numeric) #=> true [nil, true, 99].all? #=> false [].all? #=> true
Allocate size bytes of memory and return the integer memory address for the allocated memory.
Change the size of the memory allocated at the memory location addr to size bytes. Returns the memory address of the reallocated memory, which may be different than the address passed in.
Set the default id conversion object.
This is expected to be an instance such as DRb::DRbIdConv that responds to to_id and to_obj that can convert objects to and from DRb references.
See DRbServer#default_id_conv.