问题
Is there a way to "reload" or "refresh" a rubygem in memory? As i'm playing in irb, occasionally I like to modify my gem files, and if i require the same gem, it does not update into memory and gives the output "false". Currently I have to exit IRB, get back into IRB and then require the gem again, there has to be a better way...what is it?
回答1:
As others have suggested, you can use Kernel#load. However, don't waste your time finding and loading each gem file as all files that have been required are stored in $". Armed with this knowledge, here's a reload irb command:
def reload(require_regex)
$".grep(/^#{require_regex}/).each {|e| load(e) }
end
For example, if you were using the hirb gem in irb, you would simply reload with:
>> reload 'hirb'
If for whatever reason load doesn't work (it is pickier about file extensions than require is), you can re-require any file by first deleting its entry in $". With this advice the above command would be:
def reload(require_regex)
$".grep(/^#{require_regex}/).each {|e| $".delete(e) && require(e) }
end
Pick whichever works for you. Personally, I use the latter.
回答2:
load 'filename.rb'
one at a time for each that was changed...
回答3:
One way is to use Kernel#load. You can use it pretty much like Kernel#require, except that you have to explicitly include the file extension. However, it has its drawbacks (even something as simple as class Foo < Struct.new(:foo); end fails, as it is not possible to change the superclass of an class), so I would also like to know a better way to do this.
In rails you can achieve this with reload! on script/console, but I don't know what kind of magic they use.
This gist looks promising but I haven't tested it.
来源：https://stackoverflow.com/questions/3463182/reload-rubygem-in-irb