Returns a copy of str with all occurrences of pattern substituted for the second argument. The pattern is typically a Regexp; if given as a String, any regular expression metacharacters it contains will be interpreted literally, e.g. '\\d' will match a backslash followed by ‘d’, instead of a digit.
If replacement is a String it will be substituted for the matched text. It may contain back-references to the pattern’s capture groups of the form \\d, where d is a group number, or \\k<n>, where n is a group name. If it is a double-quoted string, both back-references must be preceded by an additional backslash. However, within replacement the special match variables, such as $&, will not refer to the current match.
If the second argument is a Hash, and the matched text is one of its keys, the corresponding value is the replacement string.
In the block form, the current match string is passed in as a parameter, and variables such as $1, $2, $`, $&, and $' will be set appropriately. The value returned by the block will be substituted for the match on each call.
The result inherits any tainting in the original string or any supplied replacement string.
When neither a block nor a second argument is supplied, an Enumerator is returned.
"hello".gsub(/[aeiou]/, '*') #=> "h*ll*" "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>" "hello".gsub(/./) {|s| s.ord.to_s + ' '} #=> "104 101 108 108 111 " "hello".gsub(/(?<foo>[aeiou])/, '{\k<foo>}') #=> "h{e}ll{o}" 'hello'.gsub(/[eo]/, 'e' => 3, 'o' => '*') #=> "h3ll*"
Equivalent to $_.gsub..., except that $_ will be updated if substitution occurs. Available only when -p/-n command line option specified.
The RubyVM module provides some access to Ruby internals. This module is for very limited purposes, such as debugging, prototyping, and research. Normal users must not use it.
StringScanner provides for lexical scanning operations on a String. Here is an example of its usage:
s = StringScanner.new('This is an example string') s.eos? # -> false p s.scan(/\w+/) # -> "This" p s.scan(/\w+/) # -> nil p s.scan(/\s+/) # -> " " p s.scan(/\s+/) # -> nil p s.scan(/\w+/) # -> "is" s.eos? # -> false p s.scan(/\s+/) # -> " " p s.scan(/\w+/) # -> "an" p s.scan(/\s+/) # -> " " p s.scan(/\w+/) # -> "example" p s.scan(/\s+/) # -> " " p s.scan(/\w+/) # -> "string" s.eos? # -> true p s.scan(/\s+/) # -> nil p s.scan(/\w+/) # -> nil
Scanning a string means remembering the position of a scan pointer, which is just an index. The point of scanning is to move forward a bit at a time, so matches are sought after the scan pointer; usually immediately after it.
Given the string “test string”, here are the pertinent scan pointer positions:
t e s t s t r i n g
0 1 2 ... 1
0
When you scan for a pattern (a regular expression), the match must occur at the character after the scan pointer. If you use scan_until, then the match can occur anywhere after the scan pointer. In both cases, the scan pointer moves just beyond the last character of the match, ready to scan again from the next character onwards. This is demonstrated by the example above.
Method Categories There are other methods besides the plain scanners. You can look ahead in the string without actually scanning. You can access the most recent match. You can modify the string being scanned, reset or terminate the scanner, find out or change the position of the scan pointer, skip ahead, and so on.
beginning_of_line? (bol?)
Data There are aliases to several of the methods.
An FFI closure wrapper, for handling callbacks.
closure = Class.new(Fiddle::Closure) { def call 10 end }.new(Fiddle::TYPE_INT, []) #=> #<#<Class:0x0000000150d308>:0x0000000150d240> func = Fiddle::Function.new(closure, [], Fiddle::TYPE_INT) #=> #<Fiddle::Function:0x00000001516e58> func.call #=> 10
This exception is raised if the required unicode support is missing on the system. Usually this means that the iconv library is not installed.
Command is not supported on server.
A RingServer allows a Rinda::TupleSpace to be located via UDP broadcasts. Default service location uses the following steps:
A RingServer begins listening on the network broadcast UDP address.
A RingFinger sends a UDP packet containing the DRb URI where it will listen for a reply.
The RingServer receives the UDP packet and connects back to the provided DRb URI with the DRb service.
A RingServer requires a TupleSpace:
ts = Rinda::TupleSpace.new rs = Rinda::RingServer.new
RingServer can also listen on multicast addresses for announcements. This allows multiple RingServers to run on the same host. To use network broadcast and multicast:
ts = Rinda::TupleSpace.new rs = Rinda::RingServer.new ts, %w[Socket::INADDR_ANY, 239.0.0.1 ff02::1]
Raised when a RSS::Maker attempts to use an unknown maker.
Raised when trying to activate a gem, and that gem does not exist on the system. Instead of rescuing from this class, make sure to rescue from the superclass Gem::LoadError to catch all types of load errors.
Raised when trying to activate a gem, and the gem exists on the system, but not the requested version. Instead of rescuing from this class, make sure to rescue from the superclass Gem::LoadError to catch all types of load errors.
Raised when a gem dependencies file specifies a ruby version that does not match the current version.
Gem::PathSupport facilitates the GEM_HOME and GEM_PATH environment settings to the rest of RubyGems.
Gem::StubSpecification reads the stub: line from the gemspec. This prevents us having to eval the entire gemspec in order to find out certain information.