I am doing some monkey patching in some of Ruby classes and I would like that to be included AUTOMATICALLY whenever I run ruby.
For example:
I added the method trim to String. I want to be able to do this:
ruby -e 'puts " aaaa ".trim'
I don't want to do this:
ruby -e 'require "monkey.rb"; puts " aaaa ".trim'
Is there anyway to include my monkey patches evertime I start ruby? How about irb?
Thanks!
ruby and irb both take a -r option that lets you specify a library to load when running those executables. If you want to automatically load your monkey.rb library, you can start ruby with the invocation $ ruby -r monkey (assuming monkey.rb is in your $RUBYLIB path. If you don't want to do that each time, you can set up an alias in your shell config file. For example (in Bash), you could add:
alias ruby='ruby -r monkey'
irb is probably the place where you can do this most simply. When using irb, you can use an initialization file to store anything you want run on every startup. In your home directory ("cd ~"), create a file called ".irbrc", and drop in your "require 'monkey.rb'" statement, that should do it. From then on when you start up irb, it will run anything in that script first.
Related
complete Ruby amateur here. After playing around with Ruby on various interactive online coding environments, I thought I'd try to set up Ruby on my Windows in the same way I've set up Python (using Atom and Terminal-Plus). After being frustrated and Googling for answers the past 3 hours, I thought I'd bring my question here.
Using Python, I can save a file (test.py) in Atom, and execute it using Terminal-Plus by typing:
py -i test.py
And this would create an interactive shell where I can call any functions I've stored inside my test Python script. I've learnt that I can do a similar thing with Ruby (for a test file test.rb) using:
ruby -r test.rb
but this yields the following error:
C:/Ruby21- x64/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such
file -- test.rb (LoadError)
from C:/Ruby21-x64/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
The same thing happens if I use cmd prompt to try and execute the script. I've seen other problems like this where the person was missing a key RubyGem that they were trying to call, but my test.rb file is literally:
def xyz
for i in 1..100
puts i
end
end
I'm just trying to call a Ruby script and be able to call the functions I've stored in the script in the console, in this case xyz.
-r command line switch is used to use require to load lib as a library before executing.
Try
ruby test.rb
from inside the directory this file is located, it should work.
Sort of an odd question, but: how would one go about creating a wrapper shell script that can be used in the #! line in other scripts.
wrap.sh
#!/bin/bash
set -e
echo "wrapper!"
exec ruby "$#"
test.rb
#!/usr/bin/env wrap.sh
puts RUBY_VERSION
puts "the ducks come from the trucks"
wrap.sh is in the path, and test.rb is marked as executable.
Now I do:
./test.rb
wrapper!
ruby: no Ruby script found in input (LoadError)
The goal is to execute the ruby script via the wrapper (The ruby version can be either local or comes from a traveling ruby install that is shipped along with the app).
As far as I can tell ruby is invoked, it's just unhappy with the #! in the test.rb and refuses to run the script. I cannot remove the #! because that's how the script is executed in the first place.
Any workarounds for this?
So, I cannot use rbenv/rvm/etc. There is more logic in the wrapper than this, but this is the gist of it.
Looks to me like the arguments are not being passed to Ruby in "$#". I don't think the bang-hash line is the problem.
I don't see anything in your script which actually passes the contents of test.rb to wrapper.sh, which is the bigger issue.
Perhaps the real problem can be solved by some other means? For example, is the problem you're trying to solve to run arbitrary commands prior to the invocation of any Ruby script from the command line? Perhaps it can be approached that way...
It looks like Ruby just checks that the hash-bang line contains "ruby": https://github.com/ruby/ruby/blob/v2_2_2/ruby.c#L1580 So basically having ruby somewhere in the #! line is all it takes.
I was trying to figure out how to work the command line switch -r.
My understanding is that the code is typed out as follows:
ruby -r*nameOfRequired*
I am finding that this is not the case. When I type out the above and press enter, the terminal expects an "end of input syntax" and does not continue.
What am I missing? Does there need to be a space in between the switch and the name of the required file?
Please and thank you!
EDIT:
I am currently reading "The Well Grounded Rubyist" by David A. Black, and I came up with this question while reading the section on command line switches.
Having said that, I created a "test.rb" file, containing:
puts Date.today
Then, in the terminal, I typed out:
ruby -r date
I thought this would 'require' the date module, and then enable me to run the "test.rb" file, using ruby test.rb (given that I am in the correct directory).
Instead, the terminal cursor moves to a newline, expecting more input. Let me know if I need to clarify anything else. Thanks!
If you just type ruby -rmodule, then Ruby will load the module and wait for you to type the main program that requires that module.
If you just want to run the module and do nothing else, you can do do rubyfull-path-to-module without the -r, or ruby -rmodule -e exit, or ruby -rmodule </dev/null, or similar.
In general, the ruby command does not record any state from one run to the next, so you need to tell it every thing that it needs to know whenever you run it.
Whenever you run it, you need to tell it the main program to run or else it will expect you to type that program on the standard input. The -r does not specify the main program.
Try this:
ruby -rdate test.rb
According to ruby -h:
-rlibrary require the library, before executing your script
Without giving your script file path, it read the script from stdin.
Try following (You can omit script file path when you give -e command):
ruby -r**nameOfRequired** -e ""
Is there a way to pass ruby file, foo.rb to rails console. Expected results would be after console starts rails environment to run file.
Or any other way which would allow me to execute file in rails environment, triggered from command prompt.
Actually, the simplest way is to run it with load inside the rails console
load './path/to/foo.rb'
You can use
bundle exec rails runner "eval(File.read 'your_script.rb')"
UPDATE:
What we also have been using a lot lately is to load the rails environment from within the script itself. Consider doit.rb:
#!/usr/bin/env ruby
require "/path/to/rails_app/config/environment"
# ... do your stuff
This also works if the script or the current working directory are not within the rails app's directory.
In the meantime, this solution has been supported.
rails r PATH_TO_RUBY_FILE
Much simpler now.
Consider creating a rake task.
For code that I need to create records or support migrations, for example, I often create a rake task like that from this answer. For example:
In lib/tasks/example.rake:
namespace :example do
desc "Sample description you'd see if you ran: 'rake --tasks' in the terminal"
task create_user: :environment do
User.create! first_name: "Foo", last_name: "Bar"
end
end
And then in the terminal run:
rake example:create_user
script/console --irb=pry < test.rb > test.log
simple, dirty, and block the process at the end, but it does the job exactly like I wanted.
Of these approaches mentioned earlier, none seemed clean and ideal like you would expect a standalone script to run (not get eval-ed or piped via < redirection), but finally this works perfect for me:
(for Rails 3)
Insert at the top of your script:
#!/usr/bin/env ruby
APP_PATH = File.expand_path(appdir = '/srv/staging/strat/fundmgr/config/application', __FILE__)
require File.expand_path(appdir + '/../boot', __FILE__)
require APP_PATH
# set Rails.env here if desired
Rails.application.require_environment!
# your code here...
Of course, set your own Rails app path in the APP_PATH line.
That way, I can avoid having to enter any interactive irb or rails c and can test my script.rb from the shell prompt, before eg. scheduling it in crontab.
It smoothly supports command-line parameters, too, and minimizes the levels of wrappers before getting to your code.
CREDIT (also shows a Rails 2 example)
http://zerowidth.com/2011/03/18/standalone-script-runner-bin-scripts-in-rails.html
Here's the hack I'm using:
rr() {
rails_root="$(bundle exec rails runner "puts Rails.root")"
rp="$(relpath "$1" "$rails_root")"
bundle exec rails runner "eval(File.read '$rp')"
}
relpath() {python -c "import os.path; print os.path.relpath('$1','${2:-$PWD}')";}
Example:
cd ~/rails_project/app/helpers
rr my_script.rb
Based on #moritz's answer here. I changed it, since the working directory for File.read is the Rails project root.
I know this is some serious heresy, using python to help a ruby script. But I couldn't find a relpath method built into ruby.
Credit: relpath() was taken from #MestreLion, Convert absolute path into relative path given a current directory using Bash
I have to run a whole bunch of ruby scripts to generate some results. In which order does not matter. I just don't want to do Ruby file1.rb, Ruby file2.rb, Ruby file3.rb...one by one.
Could I write a script that group all files together and issue command only once to run them all?
I would do it ruby-style and use rake gem.
I would create file named "rakefile.rb" and this would be its content:
task :default do
FileList['file*.rb'].each { |file| ruby file }
end
Then I would call rake in my favourite shell and I would enjoy it.
Bonus: It's multiplatform.
Assuming you are using bash and all the ruby files you want to run are in the current directory you could do:
for file in `ls ./*.rb`; do
ruby $file
done
Have runall.rb contain:
(1..3).each do |i|
`ruby file#{i}.rb`
end
and call ruby runall.rb.
You could make a sh script called startruby.sh that looks like this (this example doesn't work):
ruby ruby1.rb;
ruby ruby2.rb;
etc.
And then run
sh startruby.sh
And it will lauch all the ruby script after each other.
Offcourse you can also make it more advanced with a for loop and such, but this is the easiest/quickest way.
Depends on what you want, but if you want all the files loaded together, maybe something like ...
ruby -I. -e "ARGV.each {|f| load f}" file*.rb